RARE DISEASE
Spinocerebellar ataxia type 1
Spinocerebellar ataxia type 1
Spinocerebellar ataxia type 1
Synonyms: SCA1
Synonyms: SCA1
Synonyms: SCA1
Drug discovery
2
drugs
With orphan designations
Overview
Spinocerebellar Ataxia Type 1 (SCA1) is an autosomal dominant neurodegenerative disorder caused by CAG trinucleotide repeat expansions (≥40 repeats) in the ATXN1 gene. It manifests as progressive cerebellar ataxia, dysarthria, ophthalmoplegia, and bulbar dysfunction, with onset typically in early adulthood (4th decade). Pathologically, mutant ataxin-1 protein aggregation causes Purkinje cell loss and brainstem degeneration. Survival averages 10-20 years post-symptom onset, with death often due to respiratory complications [1][4][6].
Burden
73.7% of patients require assistive devices within 10 years; 81% of SCA1 patients report ≥5 falls/year [9][14]
SF-36 physical component scores 30-40% below population norms; 86% experience fear-of-falls impacting daily life [9][14]
Economic burden: 60% require caregiver support, with 40% unable to work within 15 years of onset [9][16]
Therapies
Genetic: Antisense oligonucleotides (ASOs) targeting ATXN1 mRNA and CRISPR-based approaches in preclinical stages [3][8]
Pharmacological: Riluzole (glutamate modulation), chlorzoxazone/baclofen (ion channel modulation), and phosphodiesterase inhibitors targeting downstream pathways [3][13]
Supportive: Multidisciplinary care (speech/physiotherapy), fall prevention, and aspiration management [9][16]
Categories: rare genetic diseases, rare neurological diseases, rare ophthalmic disorders
Research Papers
329 drug discovery papers about Spinocerebellar ataxia type 1, with 6 first-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
329 drug discovery papers about Spinocerebellar ataxia type 1, with 6 first-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
2026-07-10 | Immune Activation and Glial Dysfunction in Spinocerebellar Ataxias: From Cerebellar Landscape to Disease-Driven Mechanisms and Immunomodulation.
Spinocerebellar ataxias (SCAs) comprise a clinically and genetically heterogeneous group of autosomal dominant neurodegenerative disorders. Despite the recognized role of specialized cerebellar glia in cerebellar development and dysfunction, immune activation and non-immune glial responses remain understudied in SCAs. This narrative review compiles evidence from cellular, animal, and human models on the cerebellar immune landscape and the specific pathways that drive homeostatic failure and neuroinflammatory cascades across SCA subtypes. Microgliosis emerges consistently-and often early- as a generalized feature across the SCA spectrum, preceding neurodegeneration in several subtypes. Concurrently, reactive astrogliosis extends broadly, reflecting widespread macroglial surveillance and metabolic stress regulation throughout histologically preserved gray matter, with specialized homeostatic failure of Bergmann glia in SCA1, SCA2, and SCA7. Peripheral inflammation, manifests as early as the prodromal stage and correlates with the cognitive-affective deficits in SCA2 and associates with the mutation size in SCA3, positioning it as integral to pathogenesis rather than epiphenomenal. Diverse, partially shared signaling pathways converge on multi-lineage glial breakdown and reciprocal neuroimmune crosstalk. These mechanisms involve NF-κB (SCA1,3,17), cGAS-STING (SCA2), TLR/MyD88 (SCA6), and JNK/c-Jun (SCA1,2,7). This review establishes abnormal reciprocal immune/non-immune glia crosstalk as a core pathogenic principle across SCAs, revealing novel therapeutic opportunities. In fact, targeting convergent signaling nodes such as NF-κB, or JNK pathways, holds disease-modifying potential across multiple subtypes. Future research should prioritize standardized comparative studies, longitudinal analyses linking both inflammation and non-immune glial pathology to clinical progression, and clinical trials evaluating targeted immunomodulatory and glial homeostatic-supportive agents.
2026-05-25 | Aromatic-Turmerone Analogs Activate Chaperone-Mediated Autophagy and Ameliorate Dendritic Shrinkage in Purkinje Cell Models of Spinocerebellar Ataxia
We recently demonstrated that aromatic (ar)-turmerone analogs ((E)-5-methyl-1-(p-tolyl)hexa-1,4-dien-3-one [A2] and (E)-1-(4-methoxyphenyl)-5-methylhexa-1,4-dien-3-one [A4]) activate chaperone-mediated autophagy (CMA), a pathway in the autophagy-lysosome protein degradation system, in SH-SY5Y cells. Our previous studies revealed that the impairment of CMA and microautophagy (mA), another autophagy-related pathway, and dendritic shrinkage were observed in primary cultured Purkinje cells (PCs) expressing causal proteins of spinocerebellar ataxia (SCA), an autosomal dominant neurodegenerative disease. In the present study, we first investigated the effects of A2 and A4 on lysosomal protein degradation and dendritic morphology in cerebellar primary cultured PCs. Both compounds enhanced dendritic development and activated CMA in cultured PCs. These effects were significantly suppressed by the inhibitors of nuclear factor erythroid 2-related factor 2 and p38. We next examined the effects of A2 and A4 on PCs expressing several types of SCA-causing proteins (SCA model PCs). Both chemicals ameliorated the dendritic shrinkage and restored the decreased CMA/mA activity in several SCA model PCs. These findings suggest that the ar-turmerone analogs A2 and A4 improve the in vitro phenotype of SCA model PCs through CMA activation, highlighting the therapeutic potential of these analogs for various types of SCAs.
2026-05-13 | A human Staufen1 BAC transgenic mouse exhibits abnormal autophagy and neurodegeneration across the central nervous system
RNA-binding proteins (RBPs) play an essential role in development, normal functioning, and human disease. Staufen1 (STAU1) is an RBP that regulates mRNA degradation and subcellular localization, and is part of the ATXN2 protein complex. Previously, we showed that STAU1 is overabundant in patient fibroblasts and in mouse models of Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and spinocerebellar ataxia type 2 (SCA2), where it is associated with impaired autophagic flux due to STAU1-mediated upregulation of mTOR translation. STAU1 overabundance and impaired autophagy cause accumulation of biomolecular condensates and abnormal unfolded protein response (UPR). We generated a mouse model expressing the entire human STAU1 gene (hSTAU1) in a bacterial artificial chromosome (BAC) construct. hSTAU1 in these mice was expressed in cerebral hemispheres, cerebellum, and spinal cord, as well as cultured cortical neurons and cortical and spinal cord astrocytes, and microglia. Expression of hSTAU1 caused dysregulated gene expression, abnormal autophagy, glial activation, and changes in neuronal marker proteins. All of these were significantly improved by reducing STAU1 abundance by RNAi, but exacerbated in BAC-STAU1 mice crossed with Prp-TDP-43(Q331K) transgenic mice. Similar results were also obtained in eye phenotypes in ALS- and SCA2-relevant fly models upon changing staufen-1 dosage. Despite the molecular changes, we observed no overt behavioral changes in mice up to 55 weeks of age, suggesting that STAU1 may function as an epistatic modifier of neuronal degeneration. The BAC-hSTAU1 mouse will be useful for developing therapies targeting the human STAU1 gene.
2026-04-27 | Structural Mapping of Proteins Implicated in Rare Pediatric Genetic Disorders — Pediatric Research Dataset v1.0
Abstract This dataset presents curated structural sequences and disorder annotations for proteins implicated in rare pediatric genetic disorders, including MECP2 (Rett Syndrome), Ataxin-1 (Spinocerebellar Ataxia Type 1), Ataxin-3 (Machado-Joseph Disease/SCA3), and additional targets associated with inherited childhood pathologies. Each entry provides UniProt accession identifiers, intrinsic disorder classifications, and full-length amino acid sequences suitable for structural prediction, pharmacological chaperone design, and gene therapy target validation. This resource aims to support the development of precision interventions for conditions that disproportionately affect pediatric populations. Plain Language Summary Many rare childhood diseases are caused by inherited genetic mutations that produce misshapen, non-functional proteins. This dataset provides the detailed molecular sequences of proteins linked to conditions such as Rett Syndrome and spinocerebellar ataxia. By sharing this structural information openly, we help researchers study exactly how these proteins are malformed and explore potential treatments — such as drugs that help the proteins fold correctly or gene therapies that correct the underlying mutations — offering hope for children affected by these often-overlooked conditions. Related Resources Source Code: GitHub — Nexus Resonance Codex / Protein-Folding Author Profile: ORCID — James Paul Trageser Author: @jtrag on X
2026-04-14 | Long term administration of selective NMDA GluN2B receptor blocker Ro25-6981 attenuates neurodegeneration in mouse model of spinocerebellar ataxia type 1 (SCA1).
Spinocerebellar ataxia type 1 (SCA1) is caused by a CAG expansion in the gene that encodes the protein Ataxin1. Accumulation of the mutant protein in cells leads to degeneration of the cerebellum and brainstem, resulting in ataxia and culminates in failure of the circuits controlling swallowing and breathing. The nonselective NMDA receptor blocker memantine has been proposed as a potential treatment for SCA1, as it reduces excitotoxicity and neurodegeneration in other murine models of neurodegeneration. However, side effects of memantine limit its therapeutic potential, highlighting the need for more selective treatments. We have developed an SCA1 model where a lentiviral vector (LVV) selectively expresses mutant Ataxin1 in cerebellar astrocytes, triggering neuronal death through glial dysfunction and NMDA receptor-mediated excitotoxicity. Using this model, we investigate the effects of long-term administration of Ro25-6981, a selective blocker of the GluN2B subunit of glutamate receptors, typically found on extrasynaptic NMDA receptors. Chronic administration of Ro25-6981 (0.5 mg/kg day intraperitoneally) for 4 weeks prevented deterioration of motor activity in SCA1 model mice, an effect, associated with reduced neurodegeneration and decreased reactivity of Bergmann glia in the cerebellar cortex. Moreover, short-term endocannabinoid-mediated plasticity was partially preserved. Long-term blockade of NMDA receptors with Ro25-6981 caused a compensatory upregulation of expression of GluN2B and NR2A subunits. These findings suggest that specific targeting of extrasynaptic NMDA receptors with Ro25-6981 or similar drugs might offer a viable therapeutic strategy for treatment of SCA1.
2026-07-10 | Immune Activation and Glial Dysfunction in Spinocerebellar Ataxias: From Cerebellar Landscape to Disease-Driven Mechanisms and Immunomodulation.
Spinocerebellar ataxias (SCAs) comprise a clinically and genetically heterogeneous group of autosomal dominant neurodegenerative disorders. Despite the recognized role of specialized cerebellar glia in cerebellar development and dysfunction, immune activation and non-immune glial responses remain understudied in SCAs. This narrative review compiles evidence from cellular, animal, and human models on the cerebellar immune landscape and the specific pathways that drive homeostatic failure and neuroinflammatory cascades across SCA subtypes. Microgliosis emerges consistently-and often early- as a generalized feature across the SCA spectrum, preceding neurodegeneration in several subtypes. Concurrently, reactive astrogliosis extends broadly, reflecting widespread macroglial surveillance and metabolic stress regulation throughout histologically preserved gray matter, with specialized homeostatic failure of Bergmann glia in SCA1, SCA2, and SCA7. Peripheral inflammation, manifests as early as the prodromal stage and correlates with the cognitive-affective deficits in SCA2 and associates with the mutation size in SCA3, positioning it as integral to pathogenesis rather than epiphenomenal. Diverse, partially shared signaling pathways converge on multi-lineage glial breakdown and reciprocal neuroimmune crosstalk. These mechanisms involve NF-κB (SCA1,3,17), cGAS-STING (SCA2), TLR/MyD88 (SCA6), and JNK/c-Jun (SCA1,2,7). This review establishes abnormal reciprocal immune/non-immune glia crosstalk as a core pathogenic principle across SCAs, revealing novel therapeutic opportunities. In fact, targeting convergent signaling nodes such as NF-κB, or JNK pathways, holds disease-modifying potential across multiple subtypes. Future research should prioritize standardized comparative studies, longitudinal analyses linking both inflammation and non-immune glial pathology to clinical progression, and clinical trials evaluating targeted immunomodulatory and glial homeostatic-supportive agents.
2026-05-25 | Aromatic-Turmerone Analogs Activate Chaperone-Mediated Autophagy and Ameliorate Dendritic Shrinkage in Purkinje Cell Models of Spinocerebellar Ataxia
We recently demonstrated that aromatic (ar)-turmerone analogs ((E)-5-methyl-1-(p-tolyl)hexa-1,4-dien-3-one [A2] and (E)-1-(4-methoxyphenyl)-5-methylhexa-1,4-dien-3-one [A4]) activate chaperone-mediated autophagy (CMA), a pathway in the autophagy-lysosome protein degradation system, in SH-SY5Y cells. Our previous studies revealed that the impairment of CMA and microautophagy (mA), another autophagy-related pathway, and dendritic shrinkage were observed in primary cultured Purkinje cells (PCs) expressing causal proteins of spinocerebellar ataxia (SCA), an autosomal dominant neurodegenerative disease. In the present study, we first investigated the effects of A2 and A4 on lysosomal protein degradation and dendritic morphology in cerebellar primary cultured PCs. Both compounds enhanced dendritic development and activated CMA in cultured PCs. These effects were significantly suppressed by the inhibitors of nuclear factor erythroid 2-related factor 2 and p38. We next examined the effects of A2 and A4 on PCs expressing several types of SCA-causing proteins (SCA model PCs). Both chemicals ameliorated the dendritic shrinkage and restored the decreased CMA/mA activity in several SCA model PCs. These findings suggest that the ar-turmerone analogs A2 and A4 improve the in vitro phenotype of SCA model PCs through CMA activation, highlighting the therapeutic potential of these analogs for various types of SCAs.
2026-05-13 | A human Staufen1 BAC transgenic mouse exhibits abnormal autophagy and neurodegeneration across the central nervous system
RNA-binding proteins (RBPs) play an essential role in development, normal functioning, and human disease. Staufen1 (STAU1) is an RBP that regulates mRNA degradation and subcellular localization, and is part of the ATXN2 protein complex. Previously, we showed that STAU1 is overabundant in patient fibroblasts and in mouse models of Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and spinocerebellar ataxia type 2 (SCA2), where it is associated with impaired autophagic flux due to STAU1-mediated upregulation of mTOR translation. STAU1 overabundance and impaired autophagy cause accumulation of biomolecular condensates and abnormal unfolded protein response (UPR). We generated a mouse model expressing the entire human STAU1 gene (hSTAU1) in a bacterial artificial chromosome (BAC) construct. hSTAU1 in these mice was expressed in cerebral hemispheres, cerebellum, and spinal cord, as well as cultured cortical neurons and cortical and spinal cord astrocytes, and microglia. Expression of hSTAU1 caused dysregulated gene expression, abnormal autophagy, glial activation, and changes in neuronal marker proteins. All of these were significantly improved by reducing STAU1 abundance by RNAi, but exacerbated in BAC-STAU1 mice crossed with Prp-TDP-43(Q331K) transgenic mice. Similar results were also obtained in eye phenotypes in ALS- and SCA2-relevant fly models upon changing staufen-1 dosage. Despite the molecular changes, we observed no overt behavioral changes in mice up to 55 weeks of age, suggesting that STAU1 may function as an epistatic modifier of neuronal degeneration. The BAC-hSTAU1 mouse will be useful for developing therapies targeting the human STAU1 gene.
2026-04-27 | Structural Mapping of Proteins Implicated in Rare Pediatric Genetic Disorders — Pediatric Research Dataset v1.0
Abstract This dataset presents curated structural sequences and disorder annotations for proteins implicated in rare pediatric genetic disorders, including MECP2 (Rett Syndrome), Ataxin-1 (Spinocerebellar Ataxia Type 1), Ataxin-3 (Machado-Joseph Disease/SCA3), and additional targets associated with inherited childhood pathologies. Each entry provides UniProt accession identifiers, intrinsic disorder classifications, and full-length amino acid sequences suitable for structural prediction, pharmacological chaperone design, and gene therapy target validation. This resource aims to support the development of precision interventions for conditions that disproportionately affect pediatric populations. Plain Language Summary Many rare childhood diseases are caused by inherited genetic mutations that produce misshapen, non-functional proteins. This dataset provides the detailed molecular sequences of proteins linked to conditions such as Rett Syndrome and spinocerebellar ataxia. By sharing this structural information openly, we help researchers study exactly how these proteins are malformed and explore potential treatments — such as drugs that help the proteins fold correctly or gene therapies that correct the underlying mutations — offering hope for children affected by these often-overlooked conditions. Related Resources Source Code: GitHub — Nexus Resonance Codex / Protein-Folding Author Profile: ORCID — James Paul Trageser Author: @jtrag on X
2026-04-14 | Long term administration of selective NMDA GluN2B receptor blocker Ro25-6981 attenuates neurodegeneration in mouse model of spinocerebellar ataxia type 1 (SCA1).
Spinocerebellar ataxia type 1 (SCA1) is caused by a CAG expansion in the gene that encodes the protein Ataxin1. Accumulation of the mutant protein in cells leads to degeneration of the cerebellum and brainstem, resulting in ataxia and culminates in failure of the circuits controlling swallowing and breathing. The nonselective NMDA receptor blocker memantine has been proposed as a potential treatment for SCA1, as it reduces excitotoxicity and neurodegeneration in other murine models of neurodegeneration. However, side effects of memantine limit its therapeutic potential, highlighting the need for more selective treatments. We have developed an SCA1 model where a lentiviral vector (LVV) selectively expresses mutant Ataxin1 in cerebellar astrocytes, triggering neuronal death through glial dysfunction and NMDA receptor-mediated excitotoxicity. Using this model, we investigate the effects of long-term administration of Ro25-6981, a selective blocker of the GluN2B subunit of glutamate receptors, typically found on extrasynaptic NMDA receptors. Chronic administration of Ro25-6981 (0.5 mg/kg day intraperitoneally) for 4 weeks prevented deterioration of motor activity in SCA1 model mice, an effect, associated with reduced neurodegeneration and decreased reactivity of Bergmann glia in the cerebellar cortex. Moreover, short-term endocannabinoid-mediated plasticity was partially preserved. Long-term blockade of NMDA receptors with Ro25-6981 caused a compensatory upregulation of expression of GluN2B and NR2A subunits. These findings suggest that specific targeting of extrasynaptic NMDA receptors with Ro25-6981 or similar drugs might offer a viable therapeutic strategy for treatment of SCA1.
Access all drug discovery papers and probability of success in trials forecasts:
Access all drug discovery papers and probability of success in trials forecasts:
Drug Discovery Landscape
2 orphan drug designations for Spinocerebellar ataxia type 1.
2 orphan drug designations for Spinocerebellar ataxia type 1.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
a single stranded 2-methoxyethyl RNA nucleotide with a full-length phosphorothioate backbone | oligonucleotides | FDA | 2025-05-09 | — | Cure Rare Disease |
stemchymal | cell therapies | FDA | 2015-12-16 | — | Steminent Biotherapeutics, Inc. |
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