RARE DISEASE
Pitt-Hopkins syndrome
Pitt-Hopkins syndrome
Pitt-Hopkins syndrome
Drug discovery
5
drugs
With orphan designations
Overview
Pitt-Hopkins Syndrome (PTHS) is a rare neurodevelopmental disorder caused by TCF4 gene mutations (chromosome 18q21.2), characterized by severe intellectual disability, absent/limited speech, autistic features, distinctive facies (deep-set eyes, cupid's bow lips), episodic hyperventilation/apnea, epilepsy, gastrointestinal dysfunction (chronic constipation), and motor delays. It presents with variable multisystem involvement, including microcephaly, myopia, and skeletal anomalies [1][4][12][18].
Burden
Lifelong disability: 100% require assistance for daily living; 40–50% develop drug-resistant epilepsy; 60% experience breathing crises [1][9][12].
High healthcare utilization: Frequent neurodevelopmental/psychiatric comorbidities, GI complications, and recurrent hospitalizations [14][15][18].
Caregiver impact: Severe financial/emotional strain due to 24/7 care needs and limited communication abilities [11][15][18].
Therapies
Symptom management: Antiseizure medications (e.g., levetiracetam), laxatives/prokinetics for constipation, and behavioral therapies for anxiety/ADHD [6][14][15].
Multidisciplinary care: Physical/occupational/speech therapy (focusing on AAC devices), ophthalmologic surveillance, and orthopedic interventions for scoliosis/flat feet [6][8][14].
Emerging therapies: Phase 2 trials of NNZ-2591 (IGF-1 receptor modulator) show improved social/cognitive function; preclinical gene therapy targets TCF4 restoration [3][11].
Categories: rare developmental anomalies during embryogenesis, rare genetic diseases, rare neurological diseases
Research Papers
50 drug discovery papers about Pitt-Hopkins syndrome, with 1 first-in-class and 4 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
50 drug discovery papers about Pitt-Hopkins syndrome, with 1 first-in-class and 4 next-in-class emerging drug candidates forecasted to outperform the average preclinical success rate. Recent publications:
categories:
Small molecules
small molecules
2026-06-09 | Severe Hyperventilation Apnea Spells in Pitt Hopkins Syndrome and Beyond: A Remarkable Response to IV Diamox in the ICU (P6-8.011)
To report a case of recurrent hyperventilation apnea spells in an adolescent female with TCF4+ Pitt Hopkins Syndrome, focusing on the evolving insights into its pathophysiology and the established and investigational treatment strategies.
2025-08-11 | Repurposing nicardipine leads to improved development in a young patient with Pitt-Hopkins syndrome.
We describe a drug repurposing treatment involving the use of nicardipine in a young patient with Pitt-Hopkins syndrome (a rare neurodevelopmental disorder that results from variants of TCF4 gene) as a bench-to-bedside approach. Loss of TCF4 function in Pitt-Hopkins syndrome leads to increased excitability of Nav1.8 in neurons. Nicardipine is normally used alone or together with other medicines to treat severe chest pain (angina) or high blood pressure (hypertension), and can also be used in children to treat hypertension. Nicardipine was shown to have an inhibitory effect on Nav1.8 in vitro as well as in Tcf4 +/- mice, showing promising effects on behavior, learning and memory. In this study, nicardipine was given orally for 7 months (starting dose 0.2 mg/kg/d, maximum dose 1.7 mg/kg/d). There were no significant side effects. The patient showed mild to moderate improvement in all developmental trajectories as well as in her restlessness. Repurposing nicardipine in Pitt-Hopkins syndrome patients could be a promising approach to enhance development in these often severely affected patients.
2025-06-19 | Intrinsically disordered bHLH family member TCF4 drives LLPS in a DNA-dependent manner
Abstract Transcription factor 4 (TCF4), a basic helix-loop-helix (bHLH) protein, plays a critical role in neurodevelopment and is genetically linked to disorders such as Pitt-Hopkins syndrome (PTHS) and schizophrenia. While TCF4 is known to function through sequence-specific DNA binding, the influence of its intrinsically disordered regions (IDRs) on its molecular behavior remains scattered. The TCF4 deletion mutant, lacking a fragment of the bHLH domain, forms puncta in the nucleus, which are reminiscent of patterns observed in disease-associated TCF4 mutants. Our in vitro analyses have demonstrated that the shortest human isoform of TCF4 (TCF4-I − ), which is predominant in the brain and contains extensive IDRs, undergoes liquid-liquid phase separation (LLPS) in vitro . LLPS is promoted by increased ionic strength and molecular crowding, resulting in dynamic, liquid-like condensates that coalesce and display rapid fluorescence recovery after photobleaching (FRAP). Over time, these condensates mature, exhibiting increased viscosity while retaining molecular mobility. Importantly, we show that both specific and non-specific DNA sequences dissolve TCF4 condensates. This suggests that DNA binding competitively inhibits the multivalent interactions necessary for phase separation. These findings indicate that LLPS driven by TCF4 is a reversible process, likely involved in transcriptional activation bursts. We propose that mutations that disrupt DNA binding or localization may trap TCF4 in aberrant condensates, contributing to PTHS pathogenesis through dysregulated phase behavior. Our findings offer a mechanistic link between TCF4 structural features, phase separation, and its transcriptional function, providing novel insight into how mutations in this TF may drive neurological disease through aberrant biomolecular condensation.
2024-11-01 | Tcf4 Deficiency Causes Recurrent Seizures in Mice
ABSTRACT Transcription factor 4 (TCF4) is a transcription factor that is critical for the normal development and function of the central nervous system. Haploinsufficiency of TCF4 causes Pitt-Hopkins Syndrome (PTHS), a lifelong neurodevelopmental disorder characterized by seizures and intellectual disability. To expand our currently limited understanding of TCF4 function and PTHS pathophysiology, we created a mouse model of PTHS with largely astrocyte-specific heterozygous knockout of Tcf4 . These mice developed severe recurrent seizures and had decreased lifespans. In addition, we found that these mice had astrogliosis as well as increased neuronal activity in the cortex, hippocampus, amygdala, and hypothalamus. Furthermore, single nucleus RNA sequencing analysis revealed global changes in the gene expression profiles of excitatory neurons, inhibitory neurons, astrocytes, and oligodendrocytes of PTHS compared to wild-type mice. Overall, this is the first report of a PTHS mouse model with seizures, providing the field with a tool to investigate the mechanisms of PTHS development and progression and develop therapeutics for PTHS and its associated epilepsy. HIGHLIGHTS Novel PTHS mouse model that targets astrocytes develops epilepsy PTHS mice exhibit astrogliosis and increased neuron activity Changes in gene expression profile observed in PTHS mice across neurons and glial cells
2024-05-19 | A case of Pitt-Hopkins syndrome: psychopharmacological approach for anxiety, insomnia, and agitation.
Pitt-Hopkins syndrome (PTHS) is a rare genetic disorder resulting from TCF4 gene mutations which is characterized by dysmorphic facial features, psychomotor delay, intellectual disability, breathing anomalies, and seizures. Psychiatric conditions are occasionally seen. We present the case report of a seven-year-old PTHS patient with anxiety, insomnia, and agitation. We discuss the psychopharmacological intervention options for this patient. The present case study reports on a 7-year-old female with PTHS, autism spectrum disorder (ASD), and intellectual disability. She had insomnia, crying spells and agitation complaints. For anxiety symptoms and agitation, risperidone, fluoxetine, and clonazepam treatment were given by the neurologist which caused behavioral disinhibition, paroxysmal agitation and no benefit. After admission to our hospital, aripiprazole and hydroxyzine were prescribed for anxiety and ASD-related irritability. She showed a minimal improvement but hyperventilation attacks were still ongoing. Hydroxyzine was stopped, and quetiapine was given to eliminate sleep disturbance. Her sleep period went up to eleven hours. For the anxiety symptoms, escitalopram was prescribed. She showed improvements in sleep, diminished hyperactivity and decreased frequency of abnormal breathing spells. Also, enhancement of social communication skills like increased eye contact and response to her name was observed. Patients with genetic syndromes may have various psychiatric complaints. Psychopharmacological interventions should be administered carefully for the side effects.
proteins
2026-01-09 | Juvenile reinstatement of TCF4 in Pitt-Hopkins syndrome model mice reveals a critical window for genetic intervention.
Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder caused by haploinsufficiency of TCF4 which encodes transcription factor 4. As PTHS therapeutics advance toward clinical trials, identifying the optimal timing for treatment is crucial. Our previous research demonstrated that restoring TCF4 during embryonic or neonatal stages, corresponding to prenatal or neonatal periods in humans, improved phenotypes in a PTHS mouse model (Kim et al., 2022). However, PTHS diagnosis generally occurs much later, when infants fail to reach developmental milestones and undergo genetic testing. This raises an essential question: can genetic therapeutics initiated at more clinically relevant time points retain effectiveness? Here, we examined whether reinstating TCF4 in juvenile PTHS model mice could reverse behavioral phenotypes, simulating a gene therapy. Our findings indicate that this delayed intervention largely fails to correct most phenotypes, except for a measure of cognitive function. These results reveal phenotype-specific plasticity and underscore a narrow, early critical window for effective treatment in PTHS. Our study also identifies the hippocampus as a potential target for PTHS therapeutics and suggests that while some cognitive functions may still retain therapeutic plasticity, reversing most core PTHS symptoms may require intervention during the very early postnatal, or potentially prenatal periods, in humans.
2024-12-26 | Transcription factor TCF4: structure, function, and associated diseases.
Our understanding of human genes - particularly their structure, functions, and regulatory mechanisms - is still limited. The biological role of approximately 20 % of human proteins has not been established yet, and the molecular functions of the known part of the proteome remain poorly understood. This hinders progress in basic and applied biological and medical sciences, especially in treating hereditary diseases, which are caused by mutations and polymorphic variants in individual genes. Therefore, it is crucial to comprehend the mechanisms of protein functioning to address this problem. This further emphasizes the importance of investigating gene functions and molecular pathogenetic pathways associated with single-gene inherited diseases. This review focuses on the TCF4 gene that encodes a transcription factor crucial for nervous system development and functioning. Pathogenic variants in this gene have been linked to a rare genetic disorder, Pitt-Hopkins syndrome, and TCF4 polymorphic variants are associated with several socially significant diseases, including various psychiatric disorders. The pathogenetic mechanisms of these conditions remain unexplored, and the knowledge about TCF4 upregulation and its target genes is limited. TCF4 can be expressed in various isoforms due to the complex structure and regulation of its gene, which complicates the investigation of the protein's functions. Here, we consider the structure and functions of the TCF4 transcription factor. We discuss its potential target genes and the possible loss-of-function pathogenetic mechanisms identified in animal and cellular models of Pitt-Hopkins syndrome. The review also examines the advantages and limitations of potential therapies for Pitt-Hopkins syndrome that are based on TCF4 dosage compensation or altering the activity of TCF4 target genes.
2024-10-31 | Transcription factor 4 expression in the developing non-human primate brain: a comparative analysis with the mouse brain
Transcription factor 4 (TCF4) has been implicated in a range of neuropsychiatric disorders, including major depressive disorder, bipolar disorder, and schizophrenia. Mutations or deletions in TCF4 cause Pitt-Hopkins syndrome (PTHS), a rare neurodevelopmental disorder. A detailed understanding of its spatial expression across the developing brain is necessary for comprehending TCF4 biology and, by extension, to develop effective treatments for TCF4-associated disorders. However, most current knowledge is derived from mouse models, which are invaluable for preclinical studies but may not fully capture the complexities of human neuropsychiatric phenotypes. This study compared TCF4 expression in the developing mouse brain to its regional and cellular expression patterns in normal prenatal, neonatal, and young adult rhesus macaque brains, a species more relevant to human neurodevelopment. While the general developmental expression of TCF4 is largely conserved between macaques and mice, we saw several interspecies differences. Most notably, a distinct layered pattern of TCF4 expression was clear in the developing macaque neocortex but largely absent in the mouse brain. High TCF4 expression was seen in the inner dentate gyrus of adult mice but not in macaques. Conversely, TCF4 expression was higher in the adult macaque striatum compared to the mouse striatum. Further research is needed to show the significance of these interspecies differences. Still, they underscore the importance of integrating rodent and primate studies to comprehensively understand TCF4 function and its implications for human disorders. Moreover, the primate-specific expression patterns of TCF4 will inform genetic and other therapeutic strategies to treat TCF4-associated disorders.
2017-09-26 | The Intellectual Disability and Schizophrenia Associated Transcription Factor TCF4 Is Regulated by Neuronal Activity and Protein Kinase A
Transcription factor 4 (TCF4 also known as ITF2 or E2-2) is a basic helix-loop-helix (bHLH) protein associated with Pitt-Hopkins syndrome, intellectual disability, and schizophrenia (SCZ). Here, we show that TCF4-dependent transcription in cortical neurons cultured from embryonic rats of both sexes is induced by neuronal activity via soluble adenylyl cyclase and protein kinase A (PKA) signaling. PKA phosphorylates TCF4 directly and a PKA phosphorylation site in TCF4 is necessary for its transcriptional activity in cultured neurons and in the developing brain in vivo We also demonstrate that Gadd45g (growth arrest and DNA damage inducible gamma) is a direct target of neuronal-activity-induced, TCF4-dependent transcriptional regulation and that TCF4 missense variations identified in SCZ patients alter the transcriptional activity of TCF4 in neurons. This study identifies a new role for TCF4 as a neuronal-activity-regulated transcription factor, offering a novel perspective on the association of TCF4 with cognitive disorders.SIGNIFICANCE STATEMENT The importance of the basic helix-loop-helix transcription factor transcription factor 4 (TCF4) in the nervous system is underlined by its association with common and rare cognitive disorders. In the current study, we show that TCF4-controlled transcription in primary cortical neurons is induced by neuronal activity and protein kinase A. Our results support the hypotheses that dysregulation of neuronal-activity-dependent signaling plays a significant part in the etiology of neuropsychiatric and neurodevelopmental disorders.
2016-10-03 | Tcf4 Controls Neuronal Migration of the Cerebral Cortex through Regulation of Bmp7
Background: Transcription factor 4 (TCF4) is found to be associated with schizophrenia. TCF4 mutations also cause Pitt-Hopkins Syndrome, a neurodevelopmental disorder associated with severe mental retardation. However, the function of TCF4 during brain development remains unclear. Results: Here, we report that Tcf4 is expressed in the developing cerebral cortex. In utero suppression of Tcf4 arrested neuronal migration, leading to accumulation of ectopic neurons in the intermediate zone. Knockdown of Tcf4 impaired leading process formation. Furthermore, Bone Morphogenetic Protein 7 (Bmp7) is upregulated in Tcf4-deficient neurons. In vivo gain of function and rescue experiments demonstrated that Bmp7 is the major downstream effector of Tcf4 required for neuronal migration. Conclusion: Thus, we have uncovered a new Tcf4/Bmp7-dependent mechanism underlying neuronal migration, and provide insights into the pathogenesis of neurodevelopmental disorders.
gene therapies
2026-04-18 | Increasing MeCP2 protein in Pitt-Hopkins syndrome model (Tcf4+/-) mice does not affect abnormal myelination but induces the generation of astrocytes.
Pitt-Hopkins syndrome (PTHS) is a rare neurodevelopmental disorder that results from loss-of-function (LOF) mutations in the Transcription Factor 4 (TCF4) gene. PTHS closely resembles Rett syndrome (RTT), another neurodevelopmental disorder caused by mutations in the gene encoding Methyl CpG Binding Protein 2 (MECP2). We have recently shown that increasing MeCP2 levels, either genetically or via a viral vector approach, normalizes reciprocal behavioral phenotypes observed in Tcf4+/- and MECP2-overexpressing animals; in the current manuscript, we show that behavioral rescue also extends to a contextual fear learning task. Tcf4 heterozygous and knock-in mouse lines exhibit consistent myelination abnormalities, with an arrest of oligodendrocytes (OLs) at an immature stage. To address the hypothesis that correction of myelination defects is the potential mechanism underlying the behavioral rescue induced by MeCP2 increases in Tcf4+/- animals, we performed RNA-sequencing and protein expression studies. These experiments revealed that increasing MeCP2 does not dramatically affect the transcriptional profile induced by heterozygosity at Tcf4, as well as vice-versa, and subsequent molecular experiments suggest that OL gene expression and molecular phenotypes in Tcf4+/- animals are unchanged in the presence of an MECP2 transgene. However, we also find increased levels of Olig2 and Gfap co-expressing cells in Tcf4+/- mice in the presence of the MECP2 transgene, as well as the presence of cells with astrocytic morphology in the brains of these animals, suggesting a potential interplay of MeCP2 and TCF4 in astrocyte development.
2026-02-12 | Pitt–Hopkins Syndrome: A Comprehensive Review for Healthcare and Nursing Practice
Pitt–Hopkins syndrome (PTHS) is a rare genetic neurodevelopmental disorder characterized by severe intellectual disability, distinctive facial dysmorphism, abnormal breathing patterns, epilepsy, and gastrointestinal dysfunction. The condition is caused by pathogenic variants in the TCF4 gene located on chromosome 18q21.2. Due to its rarity and phenotypic overlap with other neurodevelopmental disorders, Pitt–Hopkins syndrome is frequently underdiagnosed. Early identification and multidisciplinary intervention are essential to optimize developmental outcomes and improve quality of life. This article presents a plagiarism-safe, language-polished review of Pitt–Hopkins syndrome, focusing on etiology, clinical manifestations, diagnosis, management, and nursing implications relevant to healthcare professionals.
2026-01-08 | The E-Protein Daughterless Regulates Olfactory Learning of Adult Drosophila melanogaster.
Daughterless (Da), the Drosophila melanogaster homolog of mammalian E-protein transcription factor 4 (TCF4), is well studied in fruit fly embryonic development but its functions in adult nervous system are poorly understood. Mutations in human TCF4 gene lead to intellectual disabilities such as Pitt-Hopkins syndrome and TCF4 has also been linked to schizophrenia. Here, to explore the roles of Da in the Drosophila mature brain, we map Da DNA binding sites and study the transcriptomics of the brains where Da function is inhibited by pan-neuronal Extramacrohaete (Emc) overexpression, in both male and female Drosophila Our transcriptome analyses reveal that in the adult brain Da regulates the expression of genes involved in behavior, memory, synaptic signaling, protein translation, and metabolic processes. Moreover, combining the RNA sequencing data with Da ChIP sequencing results indicates that genes associated with neuronal projection guidance, metabolism, and translation are direct targets of Da. In addition, we validate the involvement of Da in memory formation. Overall, our results provide valuable information about the functions of Da in the adult brain and aid in better understanding the mechanisms of TCF4-related disorders.
2024-06-15 | MeCP2 gene therapy ameliorates disease phenotype in mouse model for Pitt Hopkins syndrome.
The neurodevelopmental disorder Pitt Hopkins syndrome (PTHS) causes clinical symptoms similar to Rett syndrome (RTT) patients. However, RTT is caused by MECP2 mutations whereas mutations in the TCF4 gene lead to PTHS. The mechanistic commonalities underling these two disorders are unknown, but their shared symptomology suggest that convergent pathway-level disruption likely exists. We reprogrammed patient skin derived fibroblasts into induced neuronal progenitor cells. Interestingly, we discovered that MeCP2 levels were decreased in PTHS patient iNPCs relative to healthy controls and that both iNPCs and iAstrocytes displayed defects in function and differentiation in a mutation-specific manner. When Tcf4+/- mice were genetically crossed with mice overexpressing MeCP2, molecular and phenotypic defects were significantly ameliorated, underlining and important role of MeCP2 in PTHS pathology. Importantly, post-natal intracerebroventricular gene replacement therapy with adeno-associated viral vector serotype 9 (AAV9)-expressing MeCP2 (AAV9.P546.MeCP2) significantly improved iNPC and iAstrocyte function and effectively ameliorated histological and behavioral defects in Tcf4+/- mice. Combined, our data suggest a previously unknown role of MeCP2 in PTHS pathology and common pathways that might be affected in multiple neurodevelopmental disorders. Our work highlights potential novel therapeutic targets for PTHS, including upregulation of MeCP2 expression or its downstream targets or, potentially, MeCP2-based gene therapy.
2024-02-19 | Severe Dilated Cardiomyopathy in a Child with Pitt-Hopkins Syndrome
Abstract A 6-months old girl presented with dilated cardiomyopathy (dCMP) with severe left ventricle dysfunction. Surgical pulmonary artery banding was performed, with successful weaning of ventilator despite persistent cardiac dysfunction. Despite the lack of extra-cardiac symptoms at initial presentation, the patient progressively developed marked global developmental delay, stereotypical hand and head movements, and growth retardation, initially thought to be related to the persistent cardiac condition. SNP-array and panel testing for cardiomyopathy and lysosomal storage diseases were noncontributing. Trio exome sequencing revealed a de novo likely pathogenic variant in TCF4 establishing the molecular diagnosis of Pitt-Hopkins Syndrome (PTHS) and explaining the non-cardiac features. As far as we know, this is the first patient described with the association of dCMP and PTHS. We did not detect other known genetic etiologies for dCMP on targeted panel analysis nor in the exome. Systematic unbiased assessment of infantile dCMP patients in the future will therefore be crucial to confirm a possible relationship between TCF4 variants and dCMP. In conclusion, multidisciplinary approach in patients with dCMP contributes to novel insights. With a genetic diagnosis, precision medicine approaches including major therapeutic decisions such as heart transplantation are clearly considered differently. This makes an important difference for the patient, parents, and medical team.
antibodies
2024-03-11 | A patient with Pitt-Hopkins syndrome with concomitant common variable immunodeficiency.
In patients with 18q deletion syndrome (18q-), immunodeficiency, autoimmunity, and allergies have been described in a subset. Pitt-Hopkins syndrome represents a specific subset of patients with 18q- who have a proximal deletion involving the TCF4 gene or a TCF4 variant. Immunodeficiency has been reported in the overall 18q- population; however, immunodeficiency with Pitt-Hopkins syndrome has not been highlighted. This case report details the immunologic evaluations and the associated infections seen in a young adult with Pitt-Hopkins syndrome to underscore the challenges of managing adults with a complex phenotype who develop frequent infections. This patient with Pitt-Hopkins syndrome ultimately fulfilled the diagnostic criteria for common variable immunodeficiency. Immunoglobulin replacement has led to a somewhat improved infection pattern, although she continues to have aspiration events leading to pneumonia. This case highlights the clinical evolution of Pitt-Hopkins syndrome and serves as a reminder that immunodeficiency can occur in this syndrome.
small molecules
2026-06-09 | Severe Hyperventilation Apnea Spells in Pitt Hopkins Syndrome and Beyond: A Remarkable Response to IV Diamox in the ICU (P6-8.011)
To report a case of recurrent hyperventilation apnea spells in an adolescent female with TCF4+ Pitt Hopkins Syndrome, focusing on the evolving insights into its pathophysiology and the established and investigational treatment strategies.
2025-08-11 | Repurposing nicardipine leads to improved development in a young patient with Pitt-Hopkins syndrome.
We describe a drug repurposing treatment involving the use of nicardipine in a young patient with Pitt-Hopkins syndrome (a rare neurodevelopmental disorder that results from variants of TCF4 gene) as a bench-to-bedside approach. Loss of TCF4 function in Pitt-Hopkins syndrome leads to increased excitability of Nav1.8 in neurons. Nicardipine is normally used alone or together with other medicines to treat severe chest pain (angina) or high blood pressure (hypertension), and can also be used in children to treat hypertension. Nicardipine was shown to have an inhibitory effect on Nav1.8 in vitro as well as in Tcf4 +/- mice, showing promising effects on behavior, learning and memory. In this study, nicardipine was given orally for 7 months (starting dose 0.2 mg/kg/d, maximum dose 1.7 mg/kg/d). There were no significant side effects. The patient showed mild to moderate improvement in all developmental trajectories as well as in her restlessness. Repurposing nicardipine in Pitt-Hopkins syndrome patients could be a promising approach to enhance development in these often severely affected patients.
2025-06-19 | Intrinsically disordered bHLH family member TCF4 drives LLPS in a DNA-dependent manner
Abstract Transcription factor 4 (TCF4), a basic helix-loop-helix (bHLH) protein, plays a critical role in neurodevelopment and is genetically linked to disorders such as Pitt-Hopkins syndrome (PTHS) and schizophrenia. While TCF4 is known to function through sequence-specific DNA binding, the influence of its intrinsically disordered regions (IDRs) on its molecular behavior remains scattered. The TCF4 deletion mutant, lacking a fragment of the bHLH domain, forms puncta in the nucleus, which are reminiscent of patterns observed in disease-associated TCF4 mutants. Our in vitro analyses have demonstrated that the shortest human isoform of TCF4 (TCF4-I − ), which is predominant in the brain and contains extensive IDRs, undergoes liquid-liquid phase separation (LLPS) in vitro . LLPS is promoted by increased ionic strength and molecular crowding, resulting in dynamic, liquid-like condensates that coalesce and display rapid fluorescence recovery after photobleaching (FRAP). Over time, these condensates mature, exhibiting increased viscosity while retaining molecular mobility. Importantly, we show that both specific and non-specific DNA sequences dissolve TCF4 condensates. This suggests that DNA binding competitively inhibits the multivalent interactions necessary for phase separation. These findings indicate that LLPS driven by TCF4 is a reversible process, likely involved in transcriptional activation bursts. We propose that mutations that disrupt DNA binding or localization may trap TCF4 in aberrant condensates, contributing to PTHS pathogenesis through dysregulated phase behavior. Our findings offer a mechanistic link between TCF4 structural features, phase separation, and its transcriptional function, providing novel insight into how mutations in this TF may drive neurological disease through aberrant biomolecular condensation.
2024-11-01 | Tcf4 Deficiency Causes Recurrent Seizures in Mice
ABSTRACT Transcription factor 4 (TCF4) is a transcription factor that is critical for the normal development and function of the central nervous system. Haploinsufficiency of TCF4 causes Pitt-Hopkins Syndrome (PTHS), a lifelong neurodevelopmental disorder characterized by seizures and intellectual disability. To expand our currently limited understanding of TCF4 function and PTHS pathophysiology, we created a mouse model of PTHS with largely astrocyte-specific heterozygous knockout of Tcf4 . These mice developed severe recurrent seizures and had decreased lifespans. In addition, we found that these mice had astrogliosis as well as increased neuronal activity in the cortex, hippocampus, amygdala, and hypothalamus. Furthermore, single nucleus RNA sequencing analysis revealed global changes in the gene expression profiles of excitatory neurons, inhibitory neurons, astrocytes, and oligodendrocytes of PTHS compared to wild-type mice. Overall, this is the first report of a PTHS mouse model with seizures, providing the field with a tool to investigate the mechanisms of PTHS development and progression and develop therapeutics for PTHS and its associated epilepsy. HIGHLIGHTS Novel PTHS mouse model that targets astrocytes develops epilepsy PTHS mice exhibit astrogliosis and increased neuron activity Changes in gene expression profile observed in PTHS mice across neurons and glial cells
2024-05-19 | A case of Pitt-Hopkins syndrome: psychopharmacological approach for anxiety, insomnia, and agitation.
Pitt-Hopkins syndrome (PTHS) is a rare genetic disorder resulting from TCF4 gene mutations which is characterized by dysmorphic facial features, psychomotor delay, intellectual disability, breathing anomalies, and seizures. Psychiatric conditions are occasionally seen. We present the case report of a seven-year-old PTHS patient with anxiety, insomnia, and agitation. We discuss the psychopharmacological intervention options for this patient. The present case study reports on a 7-year-old female with PTHS, autism spectrum disorder (ASD), and intellectual disability. She had insomnia, crying spells and agitation complaints. For anxiety symptoms and agitation, risperidone, fluoxetine, and clonazepam treatment were given by the neurologist which caused behavioral disinhibition, paroxysmal agitation and no benefit. After admission to our hospital, aripiprazole and hydroxyzine were prescribed for anxiety and ASD-related irritability. She showed a minimal improvement but hyperventilation attacks were still ongoing. Hydroxyzine was stopped, and quetiapine was given to eliminate sleep disturbance. Her sleep period went up to eleven hours. For the anxiety symptoms, escitalopram was prescribed. She showed improvements in sleep, diminished hyperactivity and decreased frequency of abnormal breathing spells. Also, enhancement of social communication skills like increased eye contact and response to her name was observed. Patients with genetic syndromes may have various psychiatric complaints. Psychopharmacological interventions should be administered carefully for the side effects.
proteins
2026-01-09 | Juvenile reinstatement of TCF4 in Pitt-Hopkins syndrome model mice reveals a critical window for genetic intervention.
Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder caused by haploinsufficiency of TCF4 which encodes transcription factor 4. As PTHS therapeutics advance toward clinical trials, identifying the optimal timing for treatment is crucial. Our previous research demonstrated that restoring TCF4 during embryonic or neonatal stages, corresponding to prenatal or neonatal periods in humans, improved phenotypes in a PTHS mouse model (Kim et al., 2022). However, PTHS diagnosis generally occurs much later, when infants fail to reach developmental milestones and undergo genetic testing. This raises an essential question: can genetic therapeutics initiated at more clinically relevant time points retain effectiveness? Here, we examined whether reinstating TCF4 in juvenile PTHS model mice could reverse behavioral phenotypes, simulating a gene therapy. Our findings indicate that this delayed intervention largely fails to correct most phenotypes, except for a measure of cognitive function. These results reveal phenotype-specific plasticity and underscore a narrow, early critical window for effective treatment in PTHS. Our study also identifies the hippocampus as a potential target for PTHS therapeutics and suggests that while some cognitive functions may still retain therapeutic plasticity, reversing most core PTHS symptoms may require intervention during the very early postnatal, or potentially prenatal periods, in humans.
2024-12-26 | Transcription factor TCF4: structure, function, and associated diseases.
Our understanding of human genes - particularly their structure, functions, and regulatory mechanisms - is still limited. The biological role of approximately 20 % of human proteins has not been established yet, and the molecular functions of the known part of the proteome remain poorly understood. This hinders progress in basic and applied biological and medical sciences, especially in treating hereditary diseases, which are caused by mutations and polymorphic variants in individual genes. Therefore, it is crucial to comprehend the mechanisms of protein functioning to address this problem. This further emphasizes the importance of investigating gene functions and molecular pathogenetic pathways associated with single-gene inherited diseases. This review focuses on the TCF4 gene that encodes a transcription factor crucial for nervous system development and functioning. Pathogenic variants in this gene have been linked to a rare genetic disorder, Pitt-Hopkins syndrome, and TCF4 polymorphic variants are associated with several socially significant diseases, including various psychiatric disorders. The pathogenetic mechanisms of these conditions remain unexplored, and the knowledge about TCF4 upregulation and its target genes is limited. TCF4 can be expressed in various isoforms due to the complex structure and regulation of its gene, which complicates the investigation of the protein's functions. Here, we consider the structure and functions of the TCF4 transcription factor. We discuss its potential target genes and the possible loss-of-function pathogenetic mechanisms identified in animal and cellular models of Pitt-Hopkins syndrome. The review also examines the advantages and limitations of potential therapies for Pitt-Hopkins syndrome that are based on TCF4 dosage compensation or altering the activity of TCF4 target genes.
2024-10-31 | Transcription factor 4 expression in the developing non-human primate brain: a comparative analysis with the mouse brain
Transcription factor 4 (TCF4) has been implicated in a range of neuropsychiatric disorders, including major depressive disorder, bipolar disorder, and schizophrenia. Mutations or deletions in TCF4 cause Pitt-Hopkins syndrome (PTHS), a rare neurodevelopmental disorder. A detailed understanding of its spatial expression across the developing brain is necessary for comprehending TCF4 biology and, by extension, to develop effective treatments for TCF4-associated disorders. However, most current knowledge is derived from mouse models, which are invaluable for preclinical studies but may not fully capture the complexities of human neuropsychiatric phenotypes. This study compared TCF4 expression in the developing mouse brain to its regional and cellular expression patterns in normal prenatal, neonatal, and young adult rhesus macaque brains, a species more relevant to human neurodevelopment. While the general developmental expression of TCF4 is largely conserved between macaques and mice, we saw several interspecies differences. Most notably, a distinct layered pattern of TCF4 expression was clear in the developing macaque neocortex but largely absent in the mouse brain. High TCF4 expression was seen in the inner dentate gyrus of adult mice but not in macaques. Conversely, TCF4 expression was higher in the adult macaque striatum compared to the mouse striatum. Further research is needed to show the significance of these interspecies differences. Still, they underscore the importance of integrating rodent and primate studies to comprehensively understand TCF4 function and its implications for human disorders. Moreover, the primate-specific expression patterns of TCF4 will inform genetic and other therapeutic strategies to treat TCF4-associated disorders.
2017-09-26 | The Intellectual Disability and Schizophrenia Associated Transcription Factor TCF4 Is Regulated by Neuronal Activity and Protein Kinase A
Transcription factor 4 (TCF4 also known as ITF2 or E2-2) is a basic helix-loop-helix (bHLH) protein associated with Pitt-Hopkins syndrome, intellectual disability, and schizophrenia (SCZ). Here, we show that TCF4-dependent transcription in cortical neurons cultured from embryonic rats of both sexes is induced by neuronal activity via soluble adenylyl cyclase and protein kinase A (PKA) signaling. PKA phosphorylates TCF4 directly and a PKA phosphorylation site in TCF4 is necessary for its transcriptional activity in cultured neurons and in the developing brain in vivo We also demonstrate that Gadd45g (growth arrest and DNA damage inducible gamma) is a direct target of neuronal-activity-induced, TCF4-dependent transcriptional regulation and that TCF4 missense variations identified in SCZ patients alter the transcriptional activity of TCF4 in neurons. This study identifies a new role for TCF4 as a neuronal-activity-regulated transcription factor, offering a novel perspective on the association of TCF4 with cognitive disorders.SIGNIFICANCE STATEMENT The importance of the basic helix-loop-helix transcription factor transcription factor 4 (TCF4) in the nervous system is underlined by its association with common and rare cognitive disorders. In the current study, we show that TCF4-controlled transcription in primary cortical neurons is induced by neuronal activity and protein kinase A. Our results support the hypotheses that dysregulation of neuronal-activity-dependent signaling plays a significant part in the etiology of neuropsychiatric and neurodevelopmental disorders.
2016-10-03 | Tcf4 Controls Neuronal Migration of the Cerebral Cortex through Regulation of Bmp7
Background: Transcription factor 4 (TCF4) is found to be associated with schizophrenia. TCF4 mutations also cause Pitt-Hopkins Syndrome, a neurodevelopmental disorder associated with severe mental retardation. However, the function of TCF4 during brain development remains unclear. Results: Here, we report that Tcf4 is expressed in the developing cerebral cortex. In utero suppression of Tcf4 arrested neuronal migration, leading to accumulation of ectopic neurons in the intermediate zone. Knockdown of Tcf4 impaired leading process formation. Furthermore, Bone Morphogenetic Protein 7 (Bmp7) is upregulated in Tcf4-deficient neurons. In vivo gain of function and rescue experiments demonstrated that Bmp7 is the major downstream effector of Tcf4 required for neuronal migration. Conclusion: Thus, we have uncovered a new Tcf4/Bmp7-dependent mechanism underlying neuronal migration, and provide insights into the pathogenesis of neurodevelopmental disorders.
gene therapies
2026-04-18 | Increasing MeCP2 protein in Pitt-Hopkins syndrome model (Tcf4+/-) mice does not affect abnormal myelination but induces the generation of astrocytes.
Pitt-Hopkins syndrome (PTHS) is a rare neurodevelopmental disorder that results from loss-of-function (LOF) mutations in the Transcription Factor 4 (TCF4) gene. PTHS closely resembles Rett syndrome (RTT), another neurodevelopmental disorder caused by mutations in the gene encoding Methyl CpG Binding Protein 2 (MECP2). We have recently shown that increasing MeCP2 levels, either genetically or via a viral vector approach, normalizes reciprocal behavioral phenotypes observed in Tcf4+/- and MECP2-overexpressing animals; in the current manuscript, we show that behavioral rescue also extends to a contextual fear learning task. Tcf4 heterozygous and knock-in mouse lines exhibit consistent myelination abnormalities, with an arrest of oligodendrocytes (OLs) at an immature stage. To address the hypothesis that correction of myelination defects is the potential mechanism underlying the behavioral rescue induced by MeCP2 increases in Tcf4+/- animals, we performed RNA-sequencing and protein expression studies. These experiments revealed that increasing MeCP2 does not dramatically affect the transcriptional profile induced by heterozygosity at Tcf4, as well as vice-versa, and subsequent molecular experiments suggest that OL gene expression and molecular phenotypes in Tcf4+/- animals are unchanged in the presence of an MECP2 transgene. However, we also find increased levels of Olig2 and Gfap co-expressing cells in Tcf4+/- mice in the presence of the MECP2 transgene, as well as the presence of cells with astrocytic morphology in the brains of these animals, suggesting a potential interplay of MeCP2 and TCF4 in astrocyte development.
2026-02-12 | Pitt–Hopkins Syndrome: A Comprehensive Review for Healthcare and Nursing Practice
Pitt–Hopkins syndrome (PTHS) is a rare genetic neurodevelopmental disorder characterized by severe intellectual disability, distinctive facial dysmorphism, abnormal breathing patterns, epilepsy, and gastrointestinal dysfunction. The condition is caused by pathogenic variants in the TCF4 gene located on chromosome 18q21.2. Due to its rarity and phenotypic overlap with other neurodevelopmental disorders, Pitt–Hopkins syndrome is frequently underdiagnosed. Early identification and multidisciplinary intervention are essential to optimize developmental outcomes and improve quality of life. This article presents a plagiarism-safe, language-polished review of Pitt–Hopkins syndrome, focusing on etiology, clinical manifestations, diagnosis, management, and nursing implications relevant to healthcare professionals.
2026-01-08 | The E-Protein Daughterless Regulates Olfactory Learning of Adult Drosophila melanogaster.
Daughterless (Da), the Drosophila melanogaster homolog of mammalian E-protein transcription factor 4 (TCF4), is well studied in fruit fly embryonic development but its functions in adult nervous system are poorly understood. Mutations in human TCF4 gene lead to intellectual disabilities such as Pitt-Hopkins syndrome and TCF4 has also been linked to schizophrenia. Here, to explore the roles of Da in the Drosophila mature brain, we map Da DNA binding sites and study the transcriptomics of the brains where Da function is inhibited by pan-neuronal Extramacrohaete (Emc) overexpression, in both male and female Drosophila Our transcriptome analyses reveal that in the adult brain Da regulates the expression of genes involved in behavior, memory, synaptic signaling, protein translation, and metabolic processes. Moreover, combining the RNA sequencing data with Da ChIP sequencing results indicates that genes associated with neuronal projection guidance, metabolism, and translation are direct targets of Da. In addition, we validate the involvement of Da in memory formation. Overall, our results provide valuable information about the functions of Da in the adult brain and aid in better understanding the mechanisms of TCF4-related disorders.
2024-06-15 | MeCP2 gene therapy ameliorates disease phenotype in mouse model for Pitt Hopkins syndrome.
The neurodevelopmental disorder Pitt Hopkins syndrome (PTHS) causes clinical symptoms similar to Rett syndrome (RTT) patients. However, RTT is caused by MECP2 mutations whereas mutations in the TCF4 gene lead to PTHS. The mechanistic commonalities underling these two disorders are unknown, but their shared symptomology suggest that convergent pathway-level disruption likely exists. We reprogrammed patient skin derived fibroblasts into induced neuronal progenitor cells. Interestingly, we discovered that MeCP2 levels were decreased in PTHS patient iNPCs relative to healthy controls and that both iNPCs and iAstrocytes displayed defects in function and differentiation in a mutation-specific manner. When Tcf4+/- mice were genetically crossed with mice overexpressing MeCP2, molecular and phenotypic defects were significantly ameliorated, underlining and important role of MeCP2 in PTHS pathology. Importantly, post-natal intracerebroventricular gene replacement therapy with adeno-associated viral vector serotype 9 (AAV9)-expressing MeCP2 (AAV9.P546.MeCP2) significantly improved iNPC and iAstrocyte function and effectively ameliorated histological and behavioral defects in Tcf4+/- mice. Combined, our data suggest a previously unknown role of MeCP2 in PTHS pathology and common pathways that might be affected in multiple neurodevelopmental disorders. Our work highlights potential novel therapeutic targets for PTHS, including upregulation of MeCP2 expression or its downstream targets or, potentially, MeCP2-based gene therapy.
2024-02-19 | Severe Dilated Cardiomyopathy in a Child with Pitt-Hopkins Syndrome
Abstract A 6-months old girl presented with dilated cardiomyopathy (dCMP) with severe left ventricle dysfunction. Surgical pulmonary artery banding was performed, with successful weaning of ventilator despite persistent cardiac dysfunction. Despite the lack of extra-cardiac symptoms at initial presentation, the patient progressively developed marked global developmental delay, stereotypical hand and head movements, and growth retardation, initially thought to be related to the persistent cardiac condition. SNP-array and panel testing for cardiomyopathy and lysosomal storage diseases were noncontributing. Trio exome sequencing revealed a de novo likely pathogenic variant in TCF4 establishing the molecular diagnosis of Pitt-Hopkins Syndrome (PTHS) and explaining the non-cardiac features. As far as we know, this is the first patient described with the association of dCMP and PTHS. We did not detect other known genetic etiologies for dCMP on targeted panel analysis nor in the exome. Systematic unbiased assessment of infantile dCMP patients in the future will therefore be crucial to confirm a possible relationship between TCF4 variants and dCMP. In conclusion, multidisciplinary approach in patients with dCMP contributes to novel insights. With a genetic diagnosis, precision medicine approaches including major therapeutic decisions such as heart transplantation are clearly considered differently. This makes an important difference for the patient, parents, and medical team.
antibodies
2024-03-11 | A patient with Pitt-Hopkins syndrome with concomitant common variable immunodeficiency.
In patients with 18q deletion syndrome (18q-), immunodeficiency, autoimmunity, and allergies have been described in a subset. Pitt-Hopkins syndrome represents a specific subset of patients with 18q- who have a proximal deletion involving the TCF4 gene or a TCF4 variant. Immunodeficiency has been reported in the overall 18q- population; however, immunodeficiency with Pitt-Hopkins syndrome has not been highlighted. This case report details the immunologic evaluations and the associated infections seen in a young adult with Pitt-Hopkins syndrome to underscore the challenges of managing adults with a complex phenotype who develop frequent infections. This patient with Pitt-Hopkins syndrome ultimately fulfilled the diagnostic criteria for common variable immunodeficiency. Immunoglobulin replacement has led to a somewhat improved infection pattern, although she continues to have aspiration events leading to pneumonia. This case highlights the clinical evolution of Pitt-Hopkins syndrome and serves as a reminder that immunodeficiency can occur in this syndrome.
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
5 orphan drug designations for Pitt-Hopkins syndrome.
5 orphan drug designations for Pitt-Hopkins syndrome.
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
a recombinant adeno-associated virus serotype 9 viral vector containing the transgene encoding Transcription Factor 4 | gene therapies | FDA | 2026-03-08 | — | Mahzi Therapeutics |
Lyophilized microbiota purified from the stool of screened, healthy human donors | other | FDA | 2023-01-03 | — | Gut-Brain Axis Therapeutics |
Cyclo-L-glycyl-L-2-allylproline | small molecules | EMA | 2021-01-06 | — | Orphix Consulting GmbH |
nicardipine | small molecules | FDA | 2019-11-26 | — | Collaborations Pharmaceuticals, Inc. |
Cyclo(-L-Glycyl-L-2-Allylproline) | small molecules | FDA | 2019-10-15 | — | Neuren Pharmaceuticals, Ltd. |
Let's accelerate rare disease drug discovery
Let's accelerate drug discovery
Get access to Explority AI’s forecasts to outperform average preclinical success rates. Whether you’re expanding your R&D pipeline, evaluating a partnership, or simply have a question — we’d love to hear from you.