RARE DISEASE
CLN7 disease
CLN7 disease
CLN7 disease
Synonyms: Neuronal ceroid cipofuscinosis type 7, Turkish variant late infantile, vLINCL
Synonyms: Neuronal ceroid cipofuscinosis type 7, Turkish variant late infantile, vLINCL
Synonyms: Neuronal ceroid cipofuscinosis type 7, Turkish variant late infantile, vLINCL
Drug discovery
2
drugs
With orphan designations
Overview
CLN7 disease is a rare autosomal recessive neuronal ceroid lipofuscinosis (Batten disease) caused by mutations in the MFSD8 gene. Characterized by lysosomal dysfunction, it manifests between ages 2–7 with vision loss, myoclonus, ataxia, drug-resistant epilepsy, and speech impairment. Progressive neurodegeneration leads to motor/cognitive decline, blindness, and premature death, typically in adolescence [1][5][10].
Therapies
Supportive care: Antiseizure medications (e.g., valproate, levetiracetam), physical/occupational therapy, and gastrostomy for dysphagia [2][9].
Emerging therapies: Intrathecal AAV9-based gene therapy targeting MFSD8 shows preclinical efficacy in reducing neuropathology and extending survival in murine models [6][7].
Categories: rare genetic diseases, rare inborn errors of metabolism, rare neurological diseases
Research Papers
37 drug discovery papers about CLN7 disease, with 4 first-in-class and 3 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
37 drug discovery papers about CLN7 disease, with 4 first-in-class and 3 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
categories:
Small molecules
proteins
2026-07-01 | TTYH3 regulates a lysosomal chloride conductance and controls lysosomal fusion, autophagy and senescence
Chloride is the most abundant anion within lysosomes and plays a pivotal role in regulating lysosomal physiology and function. However, the mechanisms governing lysosomal chloride homeostasis remain largely elusive. Here, we identified TTYH3 as a regulator of lysosomal chloride permeability. TTYH3 mediates chloride efflux from the lysosomal lumen and enhances TRPML1-mediated lysosomal calcium release. Overexpression of TTYH3 results in markedly enlarged lysosomes by promoting lysosomal fusion via the Ca 2+ /CaM and HSP90 pathways. Moreover, TTYH3 enhances autophagy by inhibiting the AKT/mTOR signaling pathway and alleviates cellular senescence via activation of the ERK pathway. Notably, TTYH3 expression mitigates cellular phenotypes associated with lysosomal storage diseases caused by deficiencies in another lysosomal chloride channel CLN7. Collectively, our findings demonstrate that TTYH3 mediates a lysosomal chloride conductance and regulates lysosomal physiology and autophagy, and may serve as a potential therapeutic target for interventions in aging and lysosome-related diseases.
2025-04-10 | Genetic Reasons for Phenotypic Diversity in Neuronal Ceroid Lipofuscinoses and High-Resolution Imaging as a Marker of Retinal Disease.
To describe the clinical characteristics, natural history, genetic landscape, and phenotypic spectrum of neuronal ceroid lipofuscinosis (NCL)-associated retinal disease. Multicenter retrospective cohort study complemented by a cross-sectional examination. Twelve pediatric subjects with biallelic variants in 5 NCL-causing genes (CLN3 lysosomal/endosomal transmembrane protein [CLN3], CLN6 transmembrane ER protein [CLN6], Major facilitator superfamily domain containing 8 [MFSD8], Palmitoyl-protein thioesterase 1 ([PPT1], and tripeptidyl peptidase 1 [TPP1]). Review of clinical notes, retinal imaging, electroretinography (ERG), and molecular genetic testing. Two subjects underwent a cross-sectional examination comprising adaptive optics scanning laser ophthalmoscopy imaging of the retina and optoretinography (ORG). Clinical/demographic data, multimodal retinal imaging data, electrophysiology parameters, and molecular genetic testing. Our cohort included a diverse set of subjects with CLN3-juvenile NCL (n = 3), TPP1-late infantile NCL (n = 5), PPT1-late infantile or juvenile NCL (n = 2), CLN6-infantile NCL (n = 1), and CLN7/MFSD8-late infantile NCL (n = 1). Five novel pathogenic or likely pathogenic variants were identified. Age at presentation ranged from 2 to 16 years old (mean 7.9 years). Subjects presented with varying phenotypes ranging from severe neurocognitive features (n = 8; 67%), including seizures and developmental delays and regressions, to nonsyndromic retinal dystrophies (n = 2; 17%). Visual acuities at presentation ranged from light perception to 20/20. In those with recordable ERGs, the traces were electronegative and suggestive of early cone dysfunction. Fundus imaging and OCTs demonstrated outer retinal loss that varied with underlying genotype. High-resolution adaptive optics imaging and functional measures with ORG in 2 subjects with atypical TPP1-associated disease revealed significantly different phenotypes of cellular structure and function that could be followed longitudinally. Our cohort data demonstrates that the underlying genetic variants drive the phenotypic diversity in different forms of NCL. Genetic testing can provide molecular diagnosis and ensure appropriate disease management and support for children and their families. With intravitreal enzyme replacement therapy on the horizon as a potential treatment option for NCL-associated retinal degeneration, precise structural and functional measures will be required to more accurately monitor disease progression. We show that adaptive optics imaging and ORG can be used as highly sensitive methods to track early retinal changes, which can be used to establish eligibility for future therapies and provide metrics for determining the efficacy of interventions on a cellular scale. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
2014-12-25 | Partial genetic suppression of a loss-of-function mutant of the neuronal ceroid lipofuscinosis-associated protease TPP1 in Dictyostelium discoideum.
Abstract Neuronal Ceroid Lipofuscinosis (NCL) is the most common childhood-onset neurodegenerative disease. NCL is inevitably fatal, and there is no current treatment. Children with NCL show progressive decline in movement, vision, and mental abilities and accumulation of autofluorescent deposits in neurons and other cell types. Late-infantile NCL is caused by mutations in the lysosomal protease tripeptdyl peptidase 1 (TPP1). TPP1 cleaves tripeptides from the N-terminus of proteins in vitro, but little is known about the physiological function of TPP1. TPP1 shows wide conservation in vertebrates but is not found in Drosophila, C. elegans, or S. cerevisiae. Here, we characterize ddTpp1, a TPP1 ortholog present in the social amoeba Dictyostelium discoideum. Lysates from cells lacking ddTpp1 show reduced but not abolished ability to cleave a TPP1 substrate, suggesting that other Dictyostelium enzymes can perform this cleavage. ddTpp1 and human TPP1 localize to the lysosome in Dictyostelium, indicating conserved function and trafficking. Cells lacking ddTpp1 show precocious multicellular development and a reduced ability to form spores during development. When cultured in autophagy-stimulating conditions, cells lacking ddTpp1 rapidly decrease in size and are less viable than wild-type cells, suggesting that one function of ddTpp1 may be to limit autophagy. Cells lacking ddTpp1 show strongly impaired development in the presence of the lysosome-perturbing drug chloroquine, and this phenotype can be suppressed by a secondary mutation in the gene stpA, which encodes a protein with some similarity to mammalian oxysterol-binding proteins (OSBPs). Together, these results suggest that targeting specific proteins may be a viable way to suppress the effects of loss of TPP1 function.
2013-01-10 | Systemic administration of tripeptidyl peptidase I in a mouse model of late infantile neuronal ceroid lipofuscinosis: effect of glycan modification.
Late-infantile neuronal ceroid lipofuscinosis (LINCL) is a recessive genetic disease of childhood caused by deficiencies in the lysosomal protease tripeptidyl peptidase I (TPP1). Disease is characterized by progressive and extensive neuronal death. One hurdle towards development of enzyme replacement therapy is delivery of TPP1 to the brain. In this study, we evaluated the effect of modifying N-linked glycans on recombinant human TPP1 on its pharmacokinetic properties after administration via tail vein injection to a mouse model of LINCL. Unmodified TPP1 exhibited a dose-dependent serum half-life of 12 min (0.12 mg) to 45 min (2 mg). Deglycosylation or modification using sodium metaperiodate oxidation and reduction with sodium borohydride increased the circulatory half-life but did not improve targeting to the brain compared to unmodified TPP1. Analysis of liver, brain, spleen, kidney and lung demonstrated that for all preparations, >95% of the recovered activity was in the liver. Interestingly, administration of a single 2 mg dose (80 mg/kg) of unmodified TPP1 resulted in ∼10% of wild-type activity in brain. This suggests that systemic administration of unmodified recombinant enzyme merits further exploration as a potential therapy for LINCL.
2009-08-18 | Palmitoyl protein thioesterase 1 modulates tumor necrosis factor alpha-induced apoptosis.
Induction of apoptosis by TNF has recently been shown to implicate proteases from lysosomal origin, the cathepsins. Here, we investigated the role in apoptosis of palmitoyl protein thioesterase 1 (PPT1), another lysosomal enzyme that depalmitoylates proteins. We show that transformed fibroblasts derived from patients with the infantile form of neuronal ceroid lipofuscinosis (INCL), a neurodegenerative disease due to deficient activity of PPT1, are partially resistant to TNF-induced cell death (57-75% cell viability vs. 15-30% for control fibroblasts). TNF-initiated proteolytic cleavage of caspase-8, Bid and caspase-3, as well as cytochrome c release was strongly attenuated in INCL fibroblasts as compared to control cells. Noteworthy, activation of p42/p44 mitogen-activated protein kinase and of transcription factor NF-kappaB by TNF, and induction of cell death by staurosporine or chemotherapeutic drugs in INCL cells were unaffected by PPT1 deficiency. Resistance to TNF-induced apoptosis was also observed in embryonic fibroblasts derived from Ppt1/Cln1-deficient mice but not from mice with a targeted deletion of Cln3 or Cln5. Finally, reconstitution of PPT1 activity in mutant cells was accompanied by resensitization to TNF-induced caspase activation and toxicity. These observations emphasize for the first time the role of PPT1 and, likely, protein depalmitoylation in the regulation of TNF-induced apoptosis.
small molecules
2026-04-28 | PPARα and RXRα in the regulation of neuronal ceroid lipofuscinosis genes: implications for Batten disease therapy
Abstract Neuronal ceroid lipofuscinosis or Batten disease comprises a category of autosomal recessive neurodegenerative disorders that primarily affect children. Mutations in different genes lead to different forms of neuronal ceroid lipofuscinoses (CLN1-14). At present, there is no established therapy to cure most of the neuronal ceroid lipofuscinoses and the treatments are symptomatic. Enzyme replacement therapy, gene therapy, stem cell transplantation, and pharmacological chaperone therapy are being tested in different animal models and human patients. Peroxisome proliferator-activated receptor alpha (PPARα) is a member of the nuclear hormone receptor superfamily, which along with its transcription partner retinoid X receptor alpha (RXRα) regulates the expression of their target genes. This review highlights the potential role of PPARα and RXRα in the regulation of CLN genes. Here, using the MatInspector program of the Genomatix software, we performed promoter analyses of all CLN genes and observed that most of the CLN genes harbor one or more potential binding sites for PPAR and RXR in their promoter region. We further grouped them according to a binding prediction of the transcription factors to indicate high affinity binding of PPAR to CLN2 , CLN3 , CLN4 , CLN5, CLN7 , CLN10 , CLN11 , CLN12 , and CLN14 . On the other hand, we observed high affinity binding of RXR to CLN1 , CLN3 , CLN6 , CLN7 , CLN8 , CLN10 , and CLN13 . Since PPARα and RXRα have been demonstrated to control the transcription of CLN2 gene, our current promoter analysis findings highlight a possible treatment strategy for neuronal ceroid lipofuscinoses using agonists of PPARα and RXRα.
2025-04-05 | STING mediates lysosomal quality control and recovery through its proton channel function and TFEB activation in lysosomal storage disorders.
Lysosomes are essential organelles for cellular homeostasis. Defective lysosomes are associated with diseases like lysosomal storage disorders (LSDs). How lysosomal defects are detected and lysosomal function restored remain incompletely understood. Here, we show that STING mediates a neuroinflammatory gene signature in three distinct LSD mouse models, Galctwi/twi, Ppt1-/-, and Cln7-/-. Transcriptomic analysis of Galctwi/twi mouse brain tissue revealed that STING also mediates the expression of lysosomal genes that are regulated by transcriptional factor EB (TFEB). Immunohistochemical and single-nucleus RNA-sequencing (snRNA-seq) analysis show that STING regulates lysosomal gene expression in microglia. Mechanistically, we show that STING activation leads to TFEB dephosphorylation, nuclear translocation, and expression of lysosomal genes. This process requires STING's proton channel function, the V-ATPase-ATG5-ATG8 cascade, and is independent of immune signaling. Furthermore, we show that the STING-TFEB axis facilitates lysosomal repair. Together, our data identify STING-TFEB as a lysosomal quality control mechanism that responds to lysosomal dysfunction.
2023-01-24 | Lysosomal Ion Channels: What Are They Good For and Are They Druggable Targets?
Lysosomes play fundamental roles in material digestion, cellular clearance, recycling, exocytosis, wound repair, Ca2+ signaling, nutrient signaling, and gene expression regulation. The organelle also serves as a hub for important signaling networks involving the mTOR and AKT kinases. Electrophysiological recording and molecular and structural studies in the past decade have uncovered several unique lysosomal ion channels and transporters, including TPCs, TMEM175, TRPMLs, CLN7, and CLC-7. They underlie the organelle's permeability to major ions, including K+, Na+, H+, Ca2+, and Cl-. The channels are regulated by numerous cellular factors, ranging from H+ in the lumen and voltage across the lysosomal membrane to ATP in the cytosol to growth factors outside the cell. Genetic variations in the channel/transporter genes are associated with diseases that include lysosomal storage diseases and neurodegenerative diseases. Recent studies with human genetics and channel activators suggest that lysosomal channels may be attractive targets for the development of therapeutics for the prevention of and intervention in human diseases.
2022-01-27 | Aberrant upregulation of the glycolytic enzyme PFKFB3 in CLN7 neuronal ceroid lipofuscinosis
CLN7 neuronal ceroid lipofuscinosis is an inherited lysosomal storage neurodegenerative disease highly prevalent in children. CLN7/MFSD8 gene encodes a lysosomal membrane glycoprotein, but the biochemical processes affected by CLN7-loss of function are unexplored thus preventing development of potential treatments. Here, we found, in the Cln7∆ex2 mouse model of CLN7 disease, that failure in autophagy causes accumulation of structurally and bioenergetically impaired neuronal mitochondria. In vivo genetic approach reveals elevated mitochondrial reactive oxygen species (mROS) in Cln7∆ex2 neurons that mediates glycolytic enzyme PFKFB3 activation and contributes to CLN7 pathogenesis. Mechanistically, mROS sustains a signaling cascade leading to protein stabilization of PFKFB3, normally unstable in healthy neurons. Administration of the highly selective PFKFB3 inhibitor AZ67 in Cln7∆ex2 mouse brain in vivo and in CLN7 patients-derived cells rectifies key disease hallmarks. Thus, aberrant upregulation of the glycolytic enzyme PFKFB3 in neurons may contribute to CLN7 pathogenesis and targeting PFKFB3 could alleviate this and other lysosomal storage diseases.
2021-08-19 | Repurposing of tamoxifen ameliorates CLN3 and CLN7 disease phenotype
Batten diseases (BDs) are a group of lysosomal storage disorders characterized by seizure, visual loss, and cognitive and motor deterioration. We discovered increased levels of globotriaosylceramide (Gb3) in cellular and murine models of CLN3 and CLN7 diseases and used fluorescent-conjugated bacterial toxins to label Gb3 to develop a cell-based high content imaging (HCI) screening assay for the repurposing of FDA-approved compounds able to reduce this accumulation within BD cells. We found that tamoxifen reduced the lysosomal accumulation of Gb3 in CLN3 and CLN7 cell models, including neuronal progenitor cells (NPCs) from CLN7 patient-derived induced pluripotent stem cells (iPSC). Here, tamoxifen exerts its action through a mechanism that involves activation of the transcription factor EB (TFEB), a master gene of lysosomal function and autophagy. In vivo administration of tamoxifen to the CLN7Δex2 mouse model reduced the accumulation of Gb3 and SCMAS, decreased neuroinflammation, and improved motor coordination. These data strongly suggest that tamoxifen may be a suitable drug to treat some types of Batten disease.
cell therapies
2026-05-28 | Cellular and molecular characterisation of MFSD8 mutations associated with the variant late-infantile NCL CLN7
Batten disease (BD), also known as neuronal ceroid lipofuscinoses (NCLs), is a collective group of inherited neurodegenerative disorders. NCLs are the most prevalent cause of dementia in children, and they are distinguished by a common symptomatology that includes epileptic seizures, visual impairment, and a progressive decline in cognitive and physical function that results in early mortality. There are currently 12 different NCLs genetically identified in humans (CLN1-CLN8, CLN10-CLN13), with four newly identified genes (CLN9, CLN14, CLCN6, and SGSH). This study specifically focused on the variant late-infantile NCL (vLINCL) CLN7, which is caused primarily by homozygous mutations in CLN7/MFSD8, a major facilitator superfamily gene. MFSD8 encodes a multispanning integral lysosomal membrane protein with 12 transmembrane domains and has recently been described as a potential chloride channel on endosomes and lysosomes. However, there is still no cure or treatment available for CLN7 disease. Additionally, there is strong evidence demonstrating that MFSD8 is involved in the pathogenesis and pathobiology of other adult dementias, such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), as well as maculopathies and retinopathies, which share common disease-causing mutations in a heterozygosity manner. Considering the emerging relevance of the use of induced pluripotent stem cells (iPSCs) as a model for the investigation of neurodegenerative diseases, in this thesis, I studied CLN7 disease employing CLN7 patient-derived iPSCs. Specifically, two iPS cell lines were utilised, which were derived from a female patient diagnosed at the age of 2.5 years, who exhibited homozygosity for the common missense mutation p.T294K and a male patient diagnosed at the age of 4.5 years, who was also homozygous for a more severe missense mutation corresponding to p.R465W. These iPS cell lines were further differentiated into Neural Progenitor Cells (NPCs), constituting a novel approach to study the variant late-infantile NCL CLN7 and providing an opportunity to examine the disease using cell types that could more closely resemble those affected in vivo. In light of previous proteomic studies conducted in CLN7 patient-derived NPCs by our group, resulting in a downregulation of several nuclear proteins and, consistent with the observation of other studies, we identify the localisation of MFSD8 in the nucleus. These findings provide evidence of the potential existence of several co-existing MFSD8 variants within the cells, suggesting that MFSD8 might exert different functions depending on the different isoform expressed and its localisation. Additionally, this work also reveals an impairment in the autophagy-lysosomal pathway and mitochondria produced by disease-causing mutations in NPCs and the improvement of these phenotypes with the use of existing compounds. Furthermore, through the study of the post-translational modifications of MFSD8 and different protein stability assays, this work also provides more evidence of the intricacy of this protein. Therefore, further studies on the potential protein binding partners of MFSD8 were conducted to gain a deeper understanding of novel signalling pathways or molecular mechanisms in which MFSD8 might be involved. In summary, this thesis provides significant insights into the cellular and molecular biology of MFSD8 through the use of a clinically relevant model, which sheds new light on future directions for the study of CLN7 disease. These findings can contribute to the development of significant therapeutic strategies to ameliorate CLN7 disease and, as a consequence, improve other adult neurodegenerative diseases which share the same disease-causing mutations as CLN7 disease.
2017-03-09 | Using the social amoeba Dictyostelium to study the functions of proteins linked to neuronal ceroid lipofuscinosis.
Neuronal ceroid lipofuscinosis (NCL), also known as Batten disease, is a debilitating neurological disorder that affects both children and adults. Thirteen genetically distinct genes have been identified that when mutated, result in abnormal lysosomal function and an excessive accumulation of ceroid lipofuscin in neurons, as well as other cell types outside of the central nervous system. The NCL family of proteins is comprised of lysosomal enzymes (PPT1/CLN1, TPP1/CLN2, CTSD/CLN10, CTSF/CLN13), proteins that peripherally associate with membranes (DNAJC5/CLN4, KCTD7/CLN14), a soluble lysosomal protein (CLN5), a protein present in the secretory pathway (PGRN/CLN11), and several proteins that display different subcellular localizations (CLN3, CLN6, MFSD8/CLN7, CLN8, ATP13A2/CLN12). Unfortunately, the precise functions of many of the NCL proteins are still unclear, which has made targeted therapy development challenging. The social amoeba Dictyostelium discoideum has emerged as an excellent model system for studying the normal functions of proteins linked to human neurological disorders. Intriguingly, the genome of this eukaryotic soil microbe encodes homologs of 11 of the 13 known genes linked to NCL. The genetic tractability of the organism, combined with its unique life cycle, makes Dictyostelium an attractive model system for studying the functions of NCL proteins. Moreover, the ability of human NCL proteins to rescue gene-deficiency phenotypes in Dictyostelium suggests that the biological pathways regulating NCL protein function are likely conserved from Dictyostelium to human. In this review, I will discuss each of the NCL homologs in Dictyostelium in turn and describe how future studies can exploit the advantages of the system by testing new hypotheses that may ultimately lead to effective therapy options for this devastating and currently untreatable neurological disorder.
2016-08-01 | Neuronal ceroid lipofuscinosis associated with an MFSD8 mutation in Chihuahuas
The neuronal ceroid lipofuscinoses (NCLs) are hereditary neurodegenerative disorders characterized by progressive declines in neurological functions, seizures, and premature death. NCLs result from mutations in at least 13 different genes. Canine versions of the NCLs can serve as important models in developing effective therapeutic interventions for these diseases. NCLs have been described in a number of dog breeds, including Chihuahuas. Studies were undertaken to further characterize the pathology of Chihuahua NCL and to verify its molecular genetic basis. Four unrelated client owned Chihuahuas from Japan, Italy and England that exhibited progressive neurological signs consistent with a diagnosis of NCL underwent neurological examinations. Brain and in some cases also retinal and heart tissues were examined postmortem for the presence of lysosomal storage bodies characteristic of NCL. The affected dogs exhibited massive accumulation of autofluorescent lysosomal storage bodies in the brain, retina and heart accompanied by brain atrophy and retinal degeneration. The dogs were screened for known canine NCL mutations previously reported in a variety of dog breeds. All 4 dogs were homozygous for the MFSD8 single base pair deletion (MFSD8:c.843delT) previously associated with NCL in a Chinese Crested dog and in 2 affected littermate Chihuahuas from Scotland. The dogs were all homozygous for the normal alleles at the other genetic loci known to cause different forms of canine NCL. The MFSD8:c.843delT mutation was not present in 57 Chihuahuas that were either clinically normal or suffered from unrelated diseases or in 1761 unaffected dogs representing 186 other breeds. Based on these data it is almost certain that the MFSD8:c.843delT mutation is the cause of NCL in Chihuahuas. Because the disorder occurred in widely separated geographic locations or in unrelated dogs from the same country, it is likely that the mutant allele is widespread among Chihuahuas. Genetic testing for this mutation in other Chihuahuas is therefore likely to identify intact dogs with the mutant allele that could be used to establish a research colony that could be used to test potential therapeutic interventions for the corresponding human disease.
2015-05-20 | Sustained Neural Stem Cell-Based Intraocular Delivery of CNTF Attenuates Photoreceptor Loss in the nclf Mouse Model of Neuronal Ceroid Lipofuscinosis
A sustained intraocular administration of neurotrophic factors is among the strategies aimed at establishing treatments for currently untreatable degenerative retinal disorders. In the present study we have analyzed the neuroprotective effects of a continuous neural stem (NS) cell-based intraocular delivery of ciliary neurotrophic factor (CNTF) on photoreceptor cells in the nclf mouse, an animal model of the neurodegenerative lysosomal storage disorder variant late infantile neuronal ceroid lipofuscinosis (vLINCL). To this aim, we genetically modified adherently cultivated NS cells with a polycistronic lentiviral vector encoding a secretable variant of CNTF together with a Venus reporter gene (CNTF-NS cells). NS cells for control experiments (control-NS cells) were modified with a vector encoding the reporter gene tdTomato. Clonal CNTF-NS and control-NS cell lines were established using fluorescent activated cell sorting and intravitreally grafted into 14 days old nclf mice at the onset of retinal degeneration. The grafted cells preferentially differentiated into astrocytes that were attached to the posterior side of the lenses and the vitreal side of the retinas and stably expressed the transgenes for at least six weeks, the latest post-transplantation time point analyzed. Integration of donor cells into host retinas, ongoing proliferation of grafted cells or adverse effects of the donor cells on the morphology of the host eyes were not observed. Quantitative analyses of host retinas two, four and six weeks after cell transplantation revealed the presence of significantly more photoreceptor cells in eyes with grafted CNTF-NS cells than in eyes with grafted control-NS cells. This is the first demonstration that a continuous intraocular administration of a neurotrophic factor attenuates retinal degeneration in an animal model of neuronal ceroid lipofuscinosis.
gene therapies
2026-07-04 | Clinical Symptoms in Late Infantile and Juvenile Onset Neuronal Ceroid Lipofuscinosis Type 7 (CLN7 Disease).
Neuronal ceroid lipofuscinosis type 7 (CLN7 disease) can present with late-infantile or juvenile onset phenotypes. Current understanding of disease progression is limited as most published data derive from case reports or case series. Our goal was to characterize clinical aspects of CLN7 disease across phenotypes. Participants with CLN7 disease were enrolled in a longitudinal observational study. We obtained medical and developmental histories, assessed adaptive behavior ability, and conducted standardized NCL-specific assessments, including the Unified Batten Disease Rating Scale and/or the Hamburg late infantile NCL rating scale. We enrolled 5 participants with late infantile onset and 2 participants with juvenile onset CLN7 disease. Those with late-infantile CLN7 disease typically demonstrated normal early development followed by a plateau in language development. Initial symptoms were commonly cognitive/learning problems (median onset 3.0 years). Developmental regression started between ages 4 and 6 years, with loss of independent ambulation and expressive language by age 6 years. In contrast, both participants with juvenile onset CLN7 disease had normal early development with vision loss as the initial symptom (ages 10-12.5 years), followed by seizure onset within 4 years. Late-infantile and juvenile onset phenotypes of CLN7 disease have distinct natural histories and progression patterns, including typical presenting symptoms, presence of developmental regression and differences in disease course. Disease progression in the juvenile cohort was more protracted compared to the late infantile cohort. Characterizing the natural history of CLN7 disease phenotypes is essential for improving early diagnosis, improving clinical management, and supporting therapeutic development for this devastating disorder.
2025-11-29 | First-in-human high dose AAV9 intrathecal gene therapy for paediatric CLN7 disease: a phase 1, open-label, single ascending dose, non-randomised clinical trial.
Neuronal Ceroid Lipofuscinoses type 7 (CLN7) is a paediatric lysosomal storage disease caused by mutations of the MFSD8 gene. Affected children have normal early development, but then suffer from progressive cognitive, motor, verbal, and visual decline. Ataxia and myoclonic epilepsy are predominant features of the condition, and there are no effective therapies. Death usually occurs by approximately age 11 years. While adeno-associated virus serotype 9 (AAV9) based gene therapy holds promise for treating monogenetic neurologic disorders, the impact of this intervention is limited by the maximum safe tolerable dose and the host immune response to the capsid and gene product. This study sought to confirm the safety of high dose intrathecal AAV-based gene therapy under a comprehensive immunosuppression regimen. This was a two-year open label, dose escalation, phase 1 first-in-human study of AAV9-based intrathecal gene therapy for CLN7. 4 participants (1 low dose, 3 high dose) were followed at regular intervals with blood work, CSF analysis, EEG, MRI, and measures of neurologic and neuropsychological function. This study provided evidence of safety for high dose intrathecal AAV9 based gene therapy in CLN7 disease under a specific immunosuppression regimen. Additionally, this study provides preliminary evidence of efficacy for this gene therapy. High dose intrathecal AAV based gene therapy can be pursued with adequate immunosuppression and monitoring for immune responses to the gene product. Additional long-term monitoring of the immune system during tapering of immunosuppression is needed to identify potential reactions to the gene product. This study was funded by The Batten's Hope Foundation, Mila's Miracle Foundation, Children's Health Dallas and Philanthropic Gifts to UT Southwestern. In addition, Emily R. Nettesheim received funding from NIH training grant 5T32GM131945-03 and Hamza Dahshi was supported in part by NIH award T32 GM152319.
2025-11-24 | Facing the challenge of effective dosing, safety, and timing of intrathecal gene therapy for neurological disorders
MFSD8 mutations cause neuronal ceroid lipofuscinosis type 7 (CLN7), a severe autosomal recessive and rapidly progressive neurodegenerative disease. Affected patients present with progressive neuronal loss manifesting with language decline, cerebral atrophy, myoclonic seizures, progressive blindness and loss of mobility in early childhood, leading to death on average by 11 years of age.1 In the January, 2026, issue of eBioMedicine, Greenberg et al.,2 report results of a two-year trial of AAV9-based intrathecal MFSD8 gene replacement therapy, representing the first treatment approach for CLN7.
2025-10-18 | Japanese siblings with neuronal ceroid lipofuscinosis type 7 showing different initial symptoms due to biallelic MFSD8 variants: A case report
Neuronal ceroid lipofuscinosis type 7 (CLN7) is caused by variants in the major facilitator superfamily domain-containing protein 8 ( MFSD8 ) gene. Research on gene therapy for CLN7 is currently ongoing, highlighting the importance of early diagnosis. There are very few detailed case reports on the clinical course of this disease. This report presents the case of Japanese siblings with CLN7, whose definitive diagnosis was achieved through genetic testing. Patient 1, a 20-year-old boy (elder brother), was diagnosed with psychomotor retardation and suspected autism spectrum disorder. He developed myoclonus and epilepsy, with brain magnetic resonance imaging (MRI) revealing cerebellar atrophy at 4.5 years of age. Seizures progressed refractorily. At age 9, he had difficulty walking, and became bedridden a year later. Patient 2, a 15-year-old boy (younger brother), began falling frequently at age 4, and developed epilepsy with visual acuity reduction at age 5. Brain MRI revealed cerebellar atrophy. The seizures progressed refractorily, and myoclonus was observed at the age of 8 years. He became bedridden shortly after. Exome sequencing identified compound heterozygous variants of MFSD8, NM_152778.2:c.599G>A, p.(Trp200*) and c.706C>A, p.(Arg236Ser) leading to the diagnosis of CLN7. In this case, a definitive diagnosis was established through genetic testing, as enzyme activity assessment and skin biopsy results were inconclusive. The diversity of the initial symptoms and the low awareness due to the rarity of the disease contributed to diagnostic delays. The accumulation of case reports is necessary, and genetic testing is highly valuable for early diagnosis.
2022-04-21 | CLN7 mutation causes aberrant redistribution of protein isoforms and contributes to Batten disease pathobiology
Abstract The variant late infantile form of the inherited neurodegenerative Batten disease (BD) is caused by mutations in the CLN7/MFSD8 gene and represents a strong candidate for gene therapy. Post-natal intracerebral administration of AAV9-hCLN7 to Cln7 Δex2 knockout mice resulted in extended lifespan but dose escalation resulted in reduced acuity in neurophysiology tests, cerebral atrophy and elevated neuroinflammation. Comparing patient and control iPSC-derived neural progenitor cells (iNPC) we discovered that CLN7 localizes to the nucleus as well as the endolysosomal network and is differentially distributed in BD iNPC. Proteomics identified a profound nuclear defect in BD iNPC that compounds with mitochondrial and lysosomal metabolic defects resulting in elevated apoptosis. We further identified a 50kDa common nuclear CLN7 isoform and a 37kDa isoform that accumulates only in BD iNPC nuclei. Our findings suggest that successful treatment of CLN7 BD will require combinatorial therapies addressing both loss and aberrant gain of protein function.
other
2024-09-27 | Joining forces to develop individualized antisense oligonucleotides for patients with brain or eye diseases: the example of the Dutch Center for RNA Therapeutics.
Antisense oligonucleotides (ASOs) offer versatile tools to modify the processing and expression levels of gene transcripts. As such, they have a high therapeutic potential for rare genetic diseases, where applicability of each ASO ranges from thousands of patients worldwide to single individuals based on the prevalence of the causative pathogenic variant. It was shown that development of individualized ASOs was feasible within an academic setting, starting with Milasen for the treatment of a patient with CLN7 Batten's disease in the USA. Inspired by this, the Dutch Center for RNA Therapeutics (DCRT) was established by three academic medical centers in the Netherlands with a track record in ASO development for progressive, genetic neurodegenerative, neurodevelopmental, and retinal disorders. The goal of the DCRT is to bundle expertise and address national ethical, regulatory, and financial issues related to ASO treatment, and ultimately to develop individualized ASOs for eligible patients with genetic diseases affecting the central nervous system in an academic, not-for-profit setting. In this perspective, we describe the establishment of the DCRT in 2020 and the achievements so far, with a specific focus on lessons learned: the need for processes and procedures, the need for global collaboration, the need to raise awareness, and the fact that N-of-1 is N-of-a-few.
2023-11-15 | Applying Lessons Learned from Developing Exon Skipping for Duchenne to Developing Individualized Exon Skipping Therapy for Patients with Neurodegenerative Diseases
Abstract Antisense oligonucleotides (ASOs) are short, modified pieces of DNA that are chemically modified. They can be used to induce exon skipping and treat Duchenne muscular dystrophy (DMD) patients by interfering with the splicing process so mutated dystrophin transcripts become readable allowing production of partially functional dystrophin proteins, rather than nonfunctional dystrophins. After over 2 decades of research, 4 ASOs are FDA approved for DMD, but clinical effects are suboptimal due to limited delivery to skeletal muscle. At the same time, ASOs for brain diseases result in much more functional impact, because local delivery allows higher exposure to the target tissue at a low dose and infrequent treatment regimen. This has opened the way to develop ASOs in an individualized setting, as was exemplified by the development of Milasen to treat a patient with CLN7 Batten disease. In this perspective paper I will share my personal journey as one of the pioneers of ASO-mediated exon skipping development for DMD, currently applying expertise gained and lessons learned along the way to develop exon skipping ASOs for eligible patients with genetic brain diseases in a national and international setting. 1 Duchenne and Antisense-Mediated Exon Skipping 2 Opportunities for Treating Central Nervous System Diseases and Developing Individualized ASOs for Central Nervous System Diseases 3 Collaborative Spirit to Develop Individualized Treatments Globally 4 Global Implementation 5 Concluding Remarks
2021-03-08 | Translating RNA Splicing Analysis into Diagnosis and Therapy
A large proportion of rare disease patients remain undiagnosed and the vast majority of such conditions remain untreatable whether diagnosed or not. RNA splicing analysis is able to increase the diagnostic rate in rare disease by identifying cryptic splicing mutations and can help in interpreting the pathogenicity of genomic variants. Whilst targeted RT-PCR analysis remains a highly sensitive tool for assessing the splicing effects of known variants, RNA-seq can provide a more comprehensive transcriptome-wide analysis of splicing. Appropriate care should be taken in RNA-seq experimental design since sample quality, processing, choice of library preparation and sequencing parameters all introduce variability. Many bioinformatic tools exist to aid both in the prediction of splicing effects from DNA sequence and in the handling of RNA-seq data for splicing analysis. Once identified, splicing abnormalities may be amenable to correction using antisense oligonucleotide compounds by masking cryptic splice sites or blocking key splice regulatory elements, or by use of alternative corrective technologies such as trans-splicing. A growing number of such drugs have started to enter clinical use, most notably nusinersen for the treatment of spinal muscular atrophy. By bringing together the fields of RNA diagnostics and antisense therapeutics, it is becoming feasible to envisage the development of a truly personalised medicine pipeline. This has already been shown to be possible in the case of milasen, an n=1 bespoke antisense drug, and the growth and convergence of these technologies means that similar therapeutic opportunities should arise in the near future.
proteins
2026-07-01 | TTYH3 regulates a lysosomal chloride conductance and controls lysosomal fusion, autophagy and senescence
Chloride is the most abundant anion within lysosomes and plays a pivotal role in regulating lysosomal physiology and function. However, the mechanisms governing lysosomal chloride homeostasis remain largely elusive. Here, we identified TTYH3 as a regulator of lysosomal chloride permeability. TTYH3 mediates chloride efflux from the lysosomal lumen and enhances TRPML1-mediated lysosomal calcium release. Overexpression of TTYH3 results in markedly enlarged lysosomes by promoting lysosomal fusion via the Ca 2+ /CaM and HSP90 pathways. Moreover, TTYH3 enhances autophagy by inhibiting the AKT/mTOR signaling pathway and alleviates cellular senescence via activation of the ERK pathway. Notably, TTYH3 expression mitigates cellular phenotypes associated with lysosomal storage diseases caused by deficiencies in another lysosomal chloride channel CLN7. Collectively, our findings demonstrate that TTYH3 mediates a lysosomal chloride conductance and regulates lysosomal physiology and autophagy, and may serve as a potential therapeutic target for interventions in aging and lysosome-related diseases.
2025-04-10 | Genetic Reasons for Phenotypic Diversity in Neuronal Ceroid Lipofuscinoses and High-Resolution Imaging as a Marker of Retinal Disease.
To describe the clinical characteristics, natural history, genetic landscape, and phenotypic spectrum of neuronal ceroid lipofuscinosis (NCL)-associated retinal disease. Multicenter retrospective cohort study complemented by a cross-sectional examination. Twelve pediatric subjects with biallelic variants in 5 NCL-causing genes (CLN3 lysosomal/endosomal transmembrane protein [CLN3], CLN6 transmembrane ER protein [CLN6], Major facilitator superfamily domain containing 8 [MFSD8], Palmitoyl-protein thioesterase 1 ([PPT1], and tripeptidyl peptidase 1 [TPP1]). Review of clinical notes, retinal imaging, electroretinography (ERG), and molecular genetic testing. Two subjects underwent a cross-sectional examination comprising adaptive optics scanning laser ophthalmoscopy imaging of the retina and optoretinography (ORG). Clinical/demographic data, multimodal retinal imaging data, electrophysiology parameters, and molecular genetic testing. Our cohort included a diverse set of subjects with CLN3-juvenile NCL (n = 3), TPP1-late infantile NCL (n = 5), PPT1-late infantile or juvenile NCL (n = 2), CLN6-infantile NCL (n = 1), and CLN7/MFSD8-late infantile NCL (n = 1). Five novel pathogenic or likely pathogenic variants were identified. Age at presentation ranged from 2 to 16 years old (mean 7.9 years). Subjects presented with varying phenotypes ranging from severe neurocognitive features (n = 8; 67%), including seizures and developmental delays and regressions, to nonsyndromic retinal dystrophies (n = 2; 17%). Visual acuities at presentation ranged from light perception to 20/20. In those with recordable ERGs, the traces were electronegative and suggestive of early cone dysfunction. Fundus imaging and OCTs demonstrated outer retinal loss that varied with underlying genotype. High-resolution adaptive optics imaging and functional measures with ORG in 2 subjects with atypical TPP1-associated disease revealed significantly different phenotypes of cellular structure and function that could be followed longitudinally. Our cohort data demonstrates that the underlying genetic variants drive the phenotypic diversity in different forms of NCL. Genetic testing can provide molecular diagnosis and ensure appropriate disease management and support for children and their families. With intravitreal enzyme replacement therapy on the horizon as a potential treatment option for NCL-associated retinal degeneration, precise structural and functional measures will be required to more accurately monitor disease progression. We show that adaptive optics imaging and ORG can be used as highly sensitive methods to track early retinal changes, which can be used to establish eligibility for future therapies and provide metrics for determining the efficacy of interventions on a cellular scale. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
2014-12-25 | Partial genetic suppression of a loss-of-function mutant of the neuronal ceroid lipofuscinosis-associated protease TPP1 in Dictyostelium discoideum.
Abstract Neuronal Ceroid Lipofuscinosis (NCL) is the most common childhood-onset neurodegenerative disease. NCL is inevitably fatal, and there is no current treatment. Children with NCL show progressive decline in movement, vision, and mental abilities and accumulation of autofluorescent deposits in neurons and other cell types. Late-infantile NCL is caused by mutations in the lysosomal protease tripeptdyl peptidase 1 (TPP1). TPP1 cleaves tripeptides from the N-terminus of proteins in vitro, but little is known about the physiological function of TPP1. TPP1 shows wide conservation in vertebrates but is not found in Drosophila, C. elegans, or S. cerevisiae. Here, we characterize ddTpp1, a TPP1 ortholog present in the social amoeba Dictyostelium discoideum. Lysates from cells lacking ddTpp1 show reduced but not abolished ability to cleave a TPP1 substrate, suggesting that other Dictyostelium enzymes can perform this cleavage. ddTpp1 and human TPP1 localize to the lysosome in Dictyostelium, indicating conserved function and trafficking. Cells lacking ddTpp1 show precocious multicellular development and a reduced ability to form spores during development. When cultured in autophagy-stimulating conditions, cells lacking ddTpp1 rapidly decrease in size and are less viable than wild-type cells, suggesting that one function of ddTpp1 may be to limit autophagy. Cells lacking ddTpp1 show strongly impaired development in the presence of the lysosome-perturbing drug chloroquine, and this phenotype can be suppressed by a secondary mutation in the gene stpA, which encodes a protein with some similarity to mammalian oxysterol-binding proteins (OSBPs). Together, these results suggest that targeting specific proteins may be a viable way to suppress the effects of loss of TPP1 function.
2013-01-10 | Systemic administration of tripeptidyl peptidase I in a mouse model of late infantile neuronal ceroid lipofuscinosis: effect of glycan modification.
Late-infantile neuronal ceroid lipofuscinosis (LINCL) is a recessive genetic disease of childhood caused by deficiencies in the lysosomal protease tripeptidyl peptidase I (TPP1). Disease is characterized by progressive and extensive neuronal death. One hurdle towards development of enzyme replacement therapy is delivery of TPP1 to the brain. In this study, we evaluated the effect of modifying N-linked glycans on recombinant human TPP1 on its pharmacokinetic properties after administration via tail vein injection to a mouse model of LINCL. Unmodified TPP1 exhibited a dose-dependent serum half-life of 12 min (0.12 mg) to 45 min (2 mg). Deglycosylation or modification using sodium metaperiodate oxidation and reduction with sodium borohydride increased the circulatory half-life but did not improve targeting to the brain compared to unmodified TPP1. Analysis of liver, brain, spleen, kidney and lung demonstrated that for all preparations, >95% of the recovered activity was in the liver. Interestingly, administration of a single 2 mg dose (80 mg/kg) of unmodified TPP1 resulted in ∼10% of wild-type activity in brain. This suggests that systemic administration of unmodified recombinant enzyme merits further exploration as a potential therapy for LINCL.
2009-08-18 | Palmitoyl protein thioesterase 1 modulates tumor necrosis factor alpha-induced apoptosis.
Induction of apoptosis by TNF has recently been shown to implicate proteases from lysosomal origin, the cathepsins. Here, we investigated the role in apoptosis of palmitoyl protein thioesterase 1 (PPT1), another lysosomal enzyme that depalmitoylates proteins. We show that transformed fibroblasts derived from patients with the infantile form of neuronal ceroid lipofuscinosis (INCL), a neurodegenerative disease due to deficient activity of PPT1, are partially resistant to TNF-induced cell death (57-75% cell viability vs. 15-30% for control fibroblasts). TNF-initiated proteolytic cleavage of caspase-8, Bid and caspase-3, as well as cytochrome c release was strongly attenuated in INCL fibroblasts as compared to control cells. Noteworthy, activation of p42/p44 mitogen-activated protein kinase and of transcription factor NF-kappaB by TNF, and induction of cell death by staurosporine or chemotherapeutic drugs in INCL cells were unaffected by PPT1 deficiency. Resistance to TNF-induced apoptosis was also observed in embryonic fibroblasts derived from Ppt1/Cln1-deficient mice but not from mice with a targeted deletion of Cln3 or Cln5. Finally, reconstitution of PPT1 activity in mutant cells was accompanied by resensitization to TNF-induced caspase activation and toxicity. These observations emphasize for the first time the role of PPT1 and, likely, protein depalmitoylation in the regulation of TNF-induced apoptosis.
small molecules
2026-04-28 | PPARα and RXRα in the regulation of neuronal ceroid lipofuscinosis genes: implications for Batten disease therapy
Abstract Neuronal ceroid lipofuscinosis or Batten disease comprises a category of autosomal recessive neurodegenerative disorders that primarily affect children. Mutations in different genes lead to different forms of neuronal ceroid lipofuscinoses (CLN1-14). At present, there is no established therapy to cure most of the neuronal ceroid lipofuscinoses and the treatments are symptomatic. Enzyme replacement therapy, gene therapy, stem cell transplantation, and pharmacological chaperone therapy are being tested in different animal models and human patients. Peroxisome proliferator-activated receptor alpha (PPARα) is a member of the nuclear hormone receptor superfamily, which along with its transcription partner retinoid X receptor alpha (RXRα) regulates the expression of their target genes. This review highlights the potential role of PPARα and RXRα in the regulation of CLN genes. Here, using the MatInspector program of the Genomatix software, we performed promoter analyses of all CLN genes and observed that most of the CLN genes harbor one or more potential binding sites for PPAR and RXR in their promoter region. We further grouped them according to a binding prediction of the transcription factors to indicate high affinity binding of PPAR to CLN2 , CLN3 , CLN4 , CLN5, CLN7 , CLN10 , CLN11 , CLN12 , and CLN14 . On the other hand, we observed high affinity binding of RXR to CLN1 , CLN3 , CLN6 , CLN7 , CLN8 , CLN10 , and CLN13 . Since PPARα and RXRα have been demonstrated to control the transcription of CLN2 gene, our current promoter analysis findings highlight a possible treatment strategy for neuronal ceroid lipofuscinoses using agonists of PPARα and RXRα.
2025-04-05 | STING mediates lysosomal quality control and recovery through its proton channel function and TFEB activation in lysosomal storage disorders.
Lysosomes are essential organelles for cellular homeostasis. Defective lysosomes are associated with diseases like lysosomal storage disorders (LSDs). How lysosomal defects are detected and lysosomal function restored remain incompletely understood. Here, we show that STING mediates a neuroinflammatory gene signature in three distinct LSD mouse models, Galctwi/twi, Ppt1-/-, and Cln7-/-. Transcriptomic analysis of Galctwi/twi mouse brain tissue revealed that STING also mediates the expression of lysosomal genes that are regulated by transcriptional factor EB (TFEB). Immunohistochemical and single-nucleus RNA-sequencing (snRNA-seq) analysis show that STING regulates lysosomal gene expression in microglia. Mechanistically, we show that STING activation leads to TFEB dephosphorylation, nuclear translocation, and expression of lysosomal genes. This process requires STING's proton channel function, the V-ATPase-ATG5-ATG8 cascade, and is independent of immune signaling. Furthermore, we show that the STING-TFEB axis facilitates lysosomal repair. Together, our data identify STING-TFEB as a lysosomal quality control mechanism that responds to lysosomal dysfunction.
2023-01-24 | Lysosomal Ion Channels: What Are They Good For and Are They Druggable Targets?
Lysosomes play fundamental roles in material digestion, cellular clearance, recycling, exocytosis, wound repair, Ca2+ signaling, nutrient signaling, and gene expression regulation. The organelle also serves as a hub for important signaling networks involving the mTOR and AKT kinases. Electrophysiological recording and molecular and structural studies in the past decade have uncovered several unique lysosomal ion channels and transporters, including TPCs, TMEM175, TRPMLs, CLN7, and CLC-7. They underlie the organelle's permeability to major ions, including K+, Na+, H+, Ca2+, and Cl-. The channels are regulated by numerous cellular factors, ranging from H+ in the lumen and voltage across the lysosomal membrane to ATP in the cytosol to growth factors outside the cell. Genetic variations in the channel/transporter genes are associated with diseases that include lysosomal storage diseases and neurodegenerative diseases. Recent studies with human genetics and channel activators suggest that lysosomal channels may be attractive targets for the development of therapeutics for the prevention of and intervention in human diseases.
2022-01-27 | Aberrant upregulation of the glycolytic enzyme PFKFB3 in CLN7 neuronal ceroid lipofuscinosis
CLN7 neuronal ceroid lipofuscinosis is an inherited lysosomal storage neurodegenerative disease highly prevalent in children. CLN7/MFSD8 gene encodes a lysosomal membrane glycoprotein, but the biochemical processes affected by CLN7-loss of function are unexplored thus preventing development of potential treatments. Here, we found, in the Cln7∆ex2 mouse model of CLN7 disease, that failure in autophagy causes accumulation of structurally and bioenergetically impaired neuronal mitochondria. In vivo genetic approach reveals elevated mitochondrial reactive oxygen species (mROS) in Cln7∆ex2 neurons that mediates glycolytic enzyme PFKFB3 activation and contributes to CLN7 pathogenesis. Mechanistically, mROS sustains a signaling cascade leading to protein stabilization of PFKFB3, normally unstable in healthy neurons. Administration of the highly selective PFKFB3 inhibitor AZ67 in Cln7∆ex2 mouse brain in vivo and in CLN7 patients-derived cells rectifies key disease hallmarks. Thus, aberrant upregulation of the glycolytic enzyme PFKFB3 in neurons may contribute to CLN7 pathogenesis and targeting PFKFB3 could alleviate this and other lysosomal storage diseases.
2021-08-19 | Repurposing of tamoxifen ameliorates CLN3 and CLN7 disease phenotype
Batten diseases (BDs) are a group of lysosomal storage disorders characterized by seizure, visual loss, and cognitive and motor deterioration. We discovered increased levels of globotriaosylceramide (Gb3) in cellular and murine models of CLN3 and CLN7 diseases and used fluorescent-conjugated bacterial toxins to label Gb3 to develop a cell-based high content imaging (HCI) screening assay for the repurposing of FDA-approved compounds able to reduce this accumulation within BD cells. We found that tamoxifen reduced the lysosomal accumulation of Gb3 in CLN3 and CLN7 cell models, including neuronal progenitor cells (NPCs) from CLN7 patient-derived induced pluripotent stem cells (iPSC). Here, tamoxifen exerts its action through a mechanism that involves activation of the transcription factor EB (TFEB), a master gene of lysosomal function and autophagy. In vivo administration of tamoxifen to the CLN7Δex2 mouse model reduced the accumulation of Gb3 and SCMAS, decreased neuroinflammation, and improved motor coordination. These data strongly suggest that tamoxifen may be a suitable drug to treat some types of Batten disease.
cell therapies
2026-05-28 | Cellular and molecular characterisation of MFSD8 mutations associated with the variant late-infantile NCL CLN7
Batten disease (BD), also known as neuronal ceroid lipofuscinoses (NCLs), is a collective group of inherited neurodegenerative disorders. NCLs are the most prevalent cause of dementia in children, and they are distinguished by a common symptomatology that includes epileptic seizures, visual impairment, and a progressive decline in cognitive and physical function that results in early mortality. There are currently 12 different NCLs genetically identified in humans (CLN1-CLN8, CLN10-CLN13), with four newly identified genes (CLN9, CLN14, CLCN6, and SGSH). This study specifically focused on the variant late-infantile NCL (vLINCL) CLN7, which is caused primarily by homozygous mutations in CLN7/MFSD8, a major facilitator superfamily gene. MFSD8 encodes a multispanning integral lysosomal membrane protein with 12 transmembrane domains and has recently been described as a potential chloride channel on endosomes and lysosomes. However, there is still no cure or treatment available for CLN7 disease. Additionally, there is strong evidence demonstrating that MFSD8 is involved in the pathogenesis and pathobiology of other adult dementias, such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), as well as maculopathies and retinopathies, which share common disease-causing mutations in a heterozygosity manner. Considering the emerging relevance of the use of induced pluripotent stem cells (iPSCs) as a model for the investigation of neurodegenerative diseases, in this thesis, I studied CLN7 disease employing CLN7 patient-derived iPSCs. Specifically, two iPS cell lines were utilised, which were derived from a female patient diagnosed at the age of 2.5 years, who exhibited homozygosity for the common missense mutation p.T294K and a male patient diagnosed at the age of 4.5 years, who was also homozygous for a more severe missense mutation corresponding to p.R465W. These iPS cell lines were further differentiated into Neural Progenitor Cells (NPCs), constituting a novel approach to study the variant late-infantile NCL CLN7 and providing an opportunity to examine the disease using cell types that could more closely resemble those affected in vivo. In light of previous proteomic studies conducted in CLN7 patient-derived NPCs by our group, resulting in a downregulation of several nuclear proteins and, consistent with the observation of other studies, we identify the localisation of MFSD8 in the nucleus. These findings provide evidence of the potential existence of several co-existing MFSD8 variants within the cells, suggesting that MFSD8 might exert different functions depending on the different isoform expressed and its localisation. Additionally, this work also reveals an impairment in the autophagy-lysosomal pathway and mitochondria produced by disease-causing mutations in NPCs and the improvement of these phenotypes with the use of existing compounds. Furthermore, through the study of the post-translational modifications of MFSD8 and different protein stability assays, this work also provides more evidence of the intricacy of this protein. Therefore, further studies on the potential protein binding partners of MFSD8 were conducted to gain a deeper understanding of novel signalling pathways or molecular mechanisms in which MFSD8 might be involved. In summary, this thesis provides significant insights into the cellular and molecular biology of MFSD8 through the use of a clinically relevant model, which sheds new light on future directions for the study of CLN7 disease. These findings can contribute to the development of significant therapeutic strategies to ameliorate CLN7 disease and, as a consequence, improve other adult neurodegenerative diseases which share the same disease-causing mutations as CLN7 disease.
2017-03-09 | Using the social amoeba Dictyostelium to study the functions of proteins linked to neuronal ceroid lipofuscinosis.
Neuronal ceroid lipofuscinosis (NCL), also known as Batten disease, is a debilitating neurological disorder that affects both children and adults. Thirteen genetically distinct genes have been identified that when mutated, result in abnormal lysosomal function and an excessive accumulation of ceroid lipofuscin in neurons, as well as other cell types outside of the central nervous system. The NCL family of proteins is comprised of lysosomal enzymes (PPT1/CLN1, TPP1/CLN2, CTSD/CLN10, CTSF/CLN13), proteins that peripherally associate with membranes (DNAJC5/CLN4, KCTD7/CLN14), a soluble lysosomal protein (CLN5), a protein present in the secretory pathway (PGRN/CLN11), and several proteins that display different subcellular localizations (CLN3, CLN6, MFSD8/CLN7, CLN8, ATP13A2/CLN12). Unfortunately, the precise functions of many of the NCL proteins are still unclear, which has made targeted therapy development challenging. The social amoeba Dictyostelium discoideum has emerged as an excellent model system for studying the normal functions of proteins linked to human neurological disorders. Intriguingly, the genome of this eukaryotic soil microbe encodes homologs of 11 of the 13 known genes linked to NCL. The genetic tractability of the organism, combined with its unique life cycle, makes Dictyostelium an attractive model system for studying the functions of NCL proteins. Moreover, the ability of human NCL proteins to rescue gene-deficiency phenotypes in Dictyostelium suggests that the biological pathways regulating NCL protein function are likely conserved from Dictyostelium to human. In this review, I will discuss each of the NCL homologs in Dictyostelium in turn and describe how future studies can exploit the advantages of the system by testing new hypotheses that may ultimately lead to effective therapy options for this devastating and currently untreatable neurological disorder.
2016-08-01 | Neuronal ceroid lipofuscinosis associated with an MFSD8 mutation in Chihuahuas
The neuronal ceroid lipofuscinoses (NCLs) are hereditary neurodegenerative disorders characterized by progressive declines in neurological functions, seizures, and premature death. NCLs result from mutations in at least 13 different genes. Canine versions of the NCLs can serve as important models in developing effective therapeutic interventions for these diseases. NCLs have been described in a number of dog breeds, including Chihuahuas. Studies were undertaken to further characterize the pathology of Chihuahua NCL and to verify its molecular genetic basis. Four unrelated client owned Chihuahuas from Japan, Italy and England that exhibited progressive neurological signs consistent with a diagnosis of NCL underwent neurological examinations. Brain and in some cases also retinal and heart tissues were examined postmortem for the presence of lysosomal storage bodies characteristic of NCL. The affected dogs exhibited massive accumulation of autofluorescent lysosomal storage bodies in the brain, retina and heart accompanied by brain atrophy and retinal degeneration. The dogs were screened for known canine NCL mutations previously reported in a variety of dog breeds. All 4 dogs were homozygous for the MFSD8 single base pair deletion (MFSD8:c.843delT) previously associated with NCL in a Chinese Crested dog and in 2 affected littermate Chihuahuas from Scotland. The dogs were all homozygous for the normal alleles at the other genetic loci known to cause different forms of canine NCL. The MFSD8:c.843delT mutation was not present in 57 Chihuahuas that were either clinically normal or suffered from unrelated diseases or in 1761 unaffected dogs representing 186 other breeds. Based on these data it is almost certain that the MFSD8:c.843delT mutation is the cause of NCL in Chihuahuas. Because the disorder occurred in widely separated geographic locations or in unrelated dogs from the same country, it is likely that the mutant allele is widespread among Chihuahuas. Genetic testing for this mutation in other Chihuahuas is therefore likely to identify intact dogs with the mutant allele that could be used to establish a research colony that could be used to test potential therapeutic interventions for the corresponding human disease.
2015-05-20 | Sustained Neural Stem Cell-Based Intraocular Delivery of CNTF Attenuates Photoreceptor Loss in the nclf Mouse Model of Neuronal Ceroid Lipofuscinosis
A sustained intraocular administration of neurotrophic factors is among the strategies aimed at establishing treatments for currently untreatable degenerative retinal disorders. In the present study we have analyzed the neuroprotective effects of a continuous neural stem (NS) cell-based intraocular delivery of ciliary neurotrophic factor (CNTF) on photoreceptor cells in the nclf mouse, an animal model of the neurodegenerative lysosomal storage disorder variant late infantile neuronal ceroid lipofuscinosis (vLINCL). To this aim, we genetically modified adherently cultivated NS cells with a polycistronic lentiviral vector encoding a secretable variant of CNTF together with a Venus reporter gene (CNTF-NS cells). NS cells for control experiments (control-NS cells) were modified with a vector encoding the reporter gene tdTomato. Clonal CNTF-NS and control-NS cell lines were established using fluorescent activated cell sorting and intravitreally grafted into 14 days old nclf mice at the onset of retinal degeneration. The grafted cells preferentially differentiated into astrocytes that were attached to the posterior side of the lenses and the vitreal side of the retinas and stably expressed the transgenes for at least six weeks, the latest post-transplantation time point analyzed. Integration of donor cells into host retinas, ongoing proliferation of grafted cells or adverse effects of the donor cells on the morphology of the host eyes were not observed. Quantitative analyses of host retinas two, four and six weeks after cell transplantation revealed the presence of significantly more photoreceptor cells in eyes with grafted CNTF-NS cells than in eyes with grafted control-NS cells. This is the first demonstration that a continuous intraocular administration of a neurotrophic factor attenuates retinal degeneration in an animal model of neuronal ceroid lipofuscinosis.
gene therapies
2026-07-04 | Clinical Symptoms in Late Infantile and Juvenile Onset Neuronal Ceroid Lipofuscinosis Type 7 (CLN7 Disease).
Neuronal ceroid lipofuscinosis type 7 (CLN7 disease) can present with late-infantile or juvenile onset phenotypes. Current understanding of disease progression is limited as most published data derive from case reports or case series. Our goal was to characterize clinical aspects of CLN7 disease across phenotypes. Participants with CLN7 disease were enrolled in a longitudinal observational study. We obtained medical and developmental histories, assessed adaptive behavior ability, and conducted standardized NCL-specific assessments, including the Unified Batten Disease Rating Scale and/or the Hamburg late infantile NCL rating scale. We enrolled 5 participants with late infantile onset and 2 participants with juvenile onset CLN7 disease. Those with late-infantile CLN7 disease typically demonstrated normal early development followed by a plateau in language development. Initial symptoms were commonly cognitive/learning problems (median onset 3.0 years). Developmental regression started between ages 4 and 6 years, with loss of independent ambulation and expressive language by age 6 years. In contrast, both participants with juvenile onset CLN7 disease had normal early development with vision loss as the initial symptom (ages 10-12.5 years), followed by seizure onset within 4 years. Late-infantile and juvenile onset phenotypes of CLN7 disease have distinct natural histories and progression patterns, including typical presenting symptoms, presence of developmental regression and differences in disease course. Disease progression in the juvenile cohort was more protracted compared to the late infantile cohort. Characterizing the natural history of CLN7 disease phenotypes is essential for improving early diagnosis, improving clinical management, and supporting therapeutic development for this devastating disorder.
2025-11-29 | First-in-human high dose AAV9 intrathecal gene therapy for paediatric CLN7 disease: a phase 1, open-label, single ascending dose, non-randomised clinical trial.
Neuronal Ceroid Lipofuscinoses type 7 (CLN7) is a paediatric lysosomal storage disease caused by mutations of the MFSD8 gene. Affected children have normal early development, but then suffer from progressive cognitive, motor, verbal, and visual decline. Ataxia and myoclonic epilepsy are predominant features of the condition, and there are no effective therapies. Death usually occurs by approximately age 11 years. While adeno-associated virus serotype 9 (AAV9) based gene therapy holds promise for treating monogenetic neurologic disorders, the impact of this intervention is limited by the maximum safe tolerable dose and the host immune response to the capsid and gene product. This study sought to confirm the safety of high dose intrathecal AAV-based gene therapy under a comprehensive immunosuppression regimen. This was a two-year open label, dose escalation, phase 1 first-in-human study of AAV9-based intrathecal gene therapy for CLN7. 4 participants (1 low dose, 3 high dose) were followed at regular intervals with blood work, CSF analysis, EEG, MRI, and measures of neurologic and neuropsychological function. This study provided evidence of safety for high dose intrathecal AAV9 based gene therapy in CLN7 disease under a specific immunosuppression regimen. Additionally, this study provides preliminary evidence of efficacy for this gene therapy. High dose intrathecal AAV based gene therapy can be pursued with adequate immunosuppression and monitoring for immune responses to the gene product. Additional long-term monitoring of the immune system during tapering of immunosuppression is needed to identify potential reactions to the gene product. This study was funded by The Batten's Hope Foundation, Mila's Miracle Foundation, Children's Health Dallas and Philanthropic Gifts to UT Southwestern. In addition, Emily R. Nettesheim received funding from NIH training grant 5T32GM131945-03 and Hamza Dahshi was supported in part by NIH award T32 GM152319.
2025-11-24 | Facing the challenge of effective dosing, safety, and timing of intrathecal gene therapy for neurological disorders
MFSD8 mutations cause neuronal ceroid lipofuscinosis type 7 (CLN7), a severe autosomal recessive and rapidly progressive neurodegenerative disease. Affected patients present with progressive neuronal loss manifesting with language decline, cerebral atrophy, myoclonic seizures, progressive blindness and loss of mobility in early childhood, leading to death on average by 11 years of age.1 In the January, 2026, issue of eBioMedicine, Greenberg et al.,2 report results of a two-year trial of AAV9-based intrathecal MFSD8 gene replacement therapy, representing the first treatment approach for CLN7.
2025-10-18 | Japanese siblings with neuronal ceroid lipofuscinosis type 7 showing different initial symptoms due to biallelic MFSD8 variants: A case report
Neuronal ceroid lipofuscinosis type 7 (CLN7) is caused by variants in the major facilitator superfamily domain-containing protein 8 ( MFSD8 ) gene. Research on gene therapy for CLN7 is currently ongoing, highlighting the importance of early diagnosis. There are very few detailed case reports on the clinical course of this disease. This report presents the case of Japanese siblings with CLN7, whose definitive diagnosis was achieved through genetic testing. Patient 1, a 20-year-old boy (elder brother), was diagnosed with psychomotor retardation and suspected autism spectrum disorder. He developed myoclonus and epilepsy, with brain magnetic resonance imaging (MRI) revealing cerebellar atrophy at 4.5 years of age. Seizures progressed refractorily. At age 9, he had difficulty walking, and became bedridden a year later. Patient 2, a 15-year-old boy (younger brother), began falling frequently at age 4, and developed epilepsy with visual acuity reduction at age 5. Brain MRI revealed cerebellar atrophy. The seizures progressed refractorily, and myoclonus was observed at the age of 8 years. He became bedridden shortly after. Exome sequencing identified compound heterozygous variants of MFSD8, NM_152778.2:c.599G>A, p.(Trp200*) and c.706C>A, p.(Arg236Ser) leading to the diagnosis of CLN7. In this case, a definitive diagnosis was established through genetic testing, as enzyme activity assessment and skin biopsy results were inconclusive. The diversity of the initial symptoms and the low awareness due to the rarity of the disease contributed to diagnostic delays. The accumulation of case reports is necessary, and genetic testing is highly valuable for early diagnosis.
2022-04-21 | CLN7 mutation causes aberrant redistribution of protein isoforms and contributes to Batten disease pathobiology
Abstract The variant late infantile form of the inherited neurodegenerative Batten disease (BD) is caused by mutations in the CLN7/MFSD8 gene and represents a strong candidate for gene therapy. Post-natal intracerebral administration of AAV9-hCLN7 to Cln7 Δex2 knockout mice resulted in extended lifespan but dose escalation resulted in reduced acuity in neurophysiology tests, cerebral atrophy and elevated neuroinflammation. Comparing patient and control iPSC-derived neural progenitor cells (iNPC) we discovered that CLN7 localizes to the nucleus as well as the endolysosomal network and is differentially distributed in BD iNPC. Proteomics identified a profound nuclear defect in BD iNPC that compounds with mitochondrial and lysosomal metabolic defects resulting in elevated apoptosis. We further identified a 50kDa common nuclear CLN7 isoform and a 37kDa isoform that accumulates only in BD iNPC nuclei. Our findings suggest that successful treatment of CLN7 BD will require combinatorial therapies addressing both loss and aberrant gain of protein function.
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2024-09-27 | Joining forces to develop individualized antisense oligonucleotides for patients with brain or eye diseases: the example of the Dutch Center for RNA Therapeutics.
Antisense oligonucleotides (ASOs) offer versatile tools to modify the processing and expression levels of gene transcripts. As such, they have a high therapeutic potential for rare genetic diseases, where applicability of each ASO ranges from thousands of patients worldwide to single individuals based on the prevalence of the causative pathogenic variant. It was shown that development of individualized ASOs was feasible within an academic setting, starting with Milasen for the treatment of a patient with CLN7 Batten's disease in the USA. Inspired by this, the Dutch Center for RNA Therapeutics (DCRT) was established by three academic medical centers in the Netherlands with a track record in ASO development for progressive, genetic neurodegenerative, neurodevelopmental, and retinal disorders. The goal of the DCRT is to bundle expertise and address national ethical, regulatory, and financial issues related to ASO treatment, and ultimately to develop individualized ASOs for eligible patients with genetic diseases affecting the central nervous system in an academic, not-for-profit setting. In this perspective, we describe the establishment of the DCRT in 2020 and the achievements so far, with a specific focus on lessons learned: the need for processes and procedures, the need for global collaboration, the need to raise awareness, and the fact that N-of-1 is N-of-a-few.
2023-11-15 | Applying Lessons Learned from Developing Exon Skipping for Duchenne to Developing Individualized Exon Skipping Therapy for Patients with Neurodegenerative Diseases
Abstract Antisense oligonucleotides (ASOs) are short, modified pieces of DNA that are chemically modified. They can be used to induce exon skipping and treat Duchenne muscular dystrophy (DMD) patients by interfering with the splicing process so mutated dystrophin transcripts become readable allowing production of partially functional dystrophin proteins, rather than nonfunctional dystrophins. After over 2 decades of research, 4 ASOs are FDA approved for DMD, but clinical effects are suboptimal due to limited delivery to skeletal muscle. At the same time, ASOs for brain diseases result in much more functional impact, because local delivery allows higher exposure to the target tissue at a low dose and infrequent treatment regimen. This has opened the way to develop ASOs in an individualized setting, as was exemplified by the development of Milasen to treat a patient with CLN7 Batten disease. In this perspective paper I will share my personal journey as one of the pioneers of ASO-mediated exon skipping development for DMD, currently applying expertise gained and lessons learned along the way to develop exon skipping ASOs for eligible patients with genetic brain diseases in a national and international setting. 1 Duchenne and Antisense-Mediated Exon Skipping 2 Opportunities for Treating Central Nervous System Diseases and Developing Individualized ASOs for Central Nervous System Diseases 3 Collaborative Spirit to Develop Individualized Treatments Globally 4 Global Implementation 5 Concluding Remarks
2021-03-08 | Translating RNA Splicing Analysis into Diagnosis and Therapy
A large proportion of rare disease patients remain undiagnosed and the vast majority of such conditions remain untreatable whether diagnosed or not. RNA splicing analysis is able to increase the diagnostic rate in rare disease by identifying cryptic splicing mutations and can help in interpreting the pathogenicity of genomic variants. Whilst targeted RT-PCR analysis remains a highly sensitive tool for assessing the splicing effects of known variants, RNA-seq can provide a more comprehensive transcriptome-wide analysis of splicing. Appropriate care should be taken in RNA-seq experimental design since sample quality, processing, choice of library preparation and sequencing parameters all introduce variability. Many bioinformatic tools exist to aid both in the prediction of splicing effects from DNA sequence and in the handling of RNA-seq data for splicing analysis. Once identified, splicing abnormalities may be amenable to correction using antisense oligonucleotide compounds by masking cryptic splice sites or blocking key splice regulatory elements, or by use of alternative corrective technologies such as trans-splicing. A growing number of such drugs have started to enter clinical use, most notably nusinersen for the treatment of spinal muscular atrophy. By bringing together the fields of RNA diagnostics and antisense therapeutics, it is becoming feasible to envisage the development of a truly personalised medicine pipeline. This has already been shown to be possible in the case of milasen, an n=1 bespoke antisense drug, and the growth and convergence of these technologies means that similar therapeutic opportunities should arise in the near future.
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Drug Discovery Landscape
2 orphan drug designations for CLN7 disease.
2 orphan drug designations for CLN7 disease.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
adeno-associated viral vector serotype 9 encoding a codon-optimized human ceroid neuronal lipofuscinosis type 7 (CLN7) transgene | gene therapies | FDA | 2024-10-29 | — | Elpida Therapeutics SPC |
An adeno-associated virus serotype 9 (AAV9) vector with engineered transgene encoding the human CLN7/MFSD8 gene for expression of active human major facilitator superfamily domain containing 8 | gene therapies | FDA | 2020-07-31 | — | Neurogene Inc. |
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