Kisho is an information platform, not a medical provider. Nothing on this site constitutes medical advice, diagnosis, or treatment recommendations. All content is aggregated from publicly available sources (including ClinicalTrials.gov, PubMed, FDA.gov, and Orphanet) and is provided for informational purposes only. Clinical trial eligibility, treatment decisions, and any health-related actions should always be discussed with a qualified healthcare professional. Kisho does not endorse any specific therapy, organization, or clinical trial. Terms of use · Privacy policy
A rare developmental anomalies syndrome characterized by severe intellectual disability and distal hypoplasia of digits, particularly of thumbs and halluces, with nail aplasia or hypoplasia. Facial dysmorphism with a pseudo-myopathic appearance has been reported, which may include high anterior hairline or low frontal hairline with central cowlick, flat forehead, ptosis, hypertelorism, downslanting palpebral fissures, epicanthal folds, ears with thick helices, broad depressed nasal bridge with anteverted nares, short columella, long philtrum, high-arched palate, broad mouth with thick vermilion border of the upper or the lower lip and downturned corners. Marked hypotonia, seizures and global developmental delay have been reported, associated with autistic spectrum disorder manifestations in some patients.
Features include always present findings: Long philtrum, Seizure, Low muscle tone (hypotonia), and Severe intellectual disability and others; and very common findings: Short columella, Short distal phalanx of finger, Hypertelorism, and Absent nail of hallux and others. 30 total HPO annotations.
Organ System | Phenotype Count | Example Features |
|---|---|---|
Brain and nerves | 4 | Seizure, Severe intellectual disability, Global developmental delay |
KCNH1 encodes potassium voltage-gated channel subfamily H member 1 (989 aa). Pore-forming (alpha) subunit of a voltage-gated delayed rectifier potassium channel that mediates outward-rectifying potassium currents which, on depolarization, reaches a steady-state level and do not inactivate. Highest expression in Brain Cerebellar Hemisphere (6.4 TPM) and Brain Cerebellum (6.0 TPM).
Temple-Baraitser syndrome is associated with mutations in the KCNH1 gene on chromosome 1.
KCNH1 is classified as a druggable target (Druggable Genome, Ion Channel, and Transporter categories) with score 0.2.
Genetic testing for KCNH1 is available. Testing is considered confirmatory for diagnosis.
Phenotype severity distribution: 12 always present features, 5 very common features, 7 common features.
Estimated prevalence: <1 in 1,000,000 (VERY_RARE).
No clinical trials have been registered for Temple-Baraitser syndrome.
5 publications have been identified in PubMed for Temple-Baraitser syndrome. Research spans Review / Meta-Analysis (40%), Basic Science / Preclinical (40%), and Case Report / Case Series (20%).
Bernert A (2026). [PMID: 41656275](https://pubmed.ncbi.nlm.nih.gov/41656275/). *Mol Brain*. [Basic Science / Preclinical]
Sundman AK (2026). [PMID: 40986435](https://pubmed.ncbi.nlm.nih.gov/40986435/). *Brain*. [Review / Meta-Analysis]
Do NM (2025). [PMID: 40604848](https://pubmed.ncbi.nlm.nih.gov/40604848/). *BMC Oral Health*. [Case Report / Case Series]
Chen D (2024). [PMID: 38372889](https://pubmed.ncbi.nlm.nih.gov/38372889/). *Hum Cell*. [Basic Science / Preclinical]
Yang X (2024). [PMID: 39210340](https://pubmed.ncbi.nlm.nih.gov/39210340/). *BMC Med Genomics*. [Review / Meta-Analysis]
Data assembled from 6 of 12 sources · Last updated Sep 18, 2026, 1:11 PM UTC
Online Mendelian Inheritance in Man
European rare disease database
Genetic and Rare Diseases Info Center
Common questions about Temple-Baraitser syndrome
Muscles | 2 | Low muscle tone (hypotonia), Myopathic facies |
Digestive system | 2 | Gastroesophageal reflux, Constipation |
Arms and legs | 1 | Short distal phalanx of finger |
Skin | 1 | Absent nail of hallux |
Heart and blood vessels | 1 | Atrial septal defect |