Features include always present findings: Everted upper lip vermilion, Delayed fine motor development, Hypertrichosis, and Thin upper lip vermilion and others; and common findings: Bilateral tonic-clonic seizure, Narrow forehead, Brachydactyly, and Deep philtrum and others.

KCNK4 encodes potassium two pore domain channel subfamily K member 4 (393 aa). K(+) channel that conducts voltage-dependent outward rectifying currents upon membrane depolarization. Highest expression in Brain Nucleus accumbens basal ganglia (14.1 TPM) and Brain Frontal Cortex BA9 (11.7 TPM).

Facial dysmorphism, hypertrichosis, epilepsy, intellectual/developmental delay, and gingival overgrowth syndrome has been associated with mutations in the KCNK4 gene on chromosome 11.

KCNK4 is classified as a druggable target (Druggable Genome and Ion Channel categories) with score 0.0.

Genetic testing for KCNK4 is available. Testing is considered supportive for diagnosis.

Phenotype severity distribution: 14 always present features, 22 common features.

Estimated prevalence: <1 in 1,000,000 (VERY_RARE).

No clinical trials have been registered for facial dysmorphism, hypertrichosis, epilepsy, intellectual/developmental delay, and gingival overgrowth syndrome.

3 publications have been identified in PubMed for facial dysmorphism, hypertrichosis, epilepsy, intellectual/developmental delay, and gingival overgrowth syndrome. Research spans Other (33%), Case Report / Case Series (33%), and Basic Science / Preclinical (33%).

Recent Publications

• Chandler N (2025). [PMID: 39394633](https://pubmed.ncbi.nlm.nih.gov/39394633/). *Prenat Diagn*. [Other]

• Yan HJ (2025). [PMID: 40230348](https://pubmed.ncbi.nlm.nih.gov/40230348/). *Front Genet*. [Case Report / Case Series]

• Docter T (2024). [PMID: 39713384](https://pubmed.ncbi.nlm.nih.gov/39713384/). *bioRxiv*. [Basic Science / Preclinical]