Features include always present findings: Poor speech, Small nail, Clinodactyly of the 4th toe, and Alopecia and others; and very common findings: Joint hypermobility, Global developmental delay, Pili torti, and Ataxia and others. 38 total HPO annotations.

HEPHL1 encodes hephaestin like 1 (1,159 aa). Is a copper-binding glycoprotein with ferroxidase activity. It oxidizes Fe(2+) to Fe(3+) without releasing radical oxygen species. May be involved in the regulation of intracellular iron content Highest expression in Esophagus Mucosa (2.0 TPM) and Vagina (1.0 TPM).

Pili torti-developmental delay-neurological abnormalities syndrome has limited evidence linking it to mutations in the HEPHL1 gene on chromosome 11.

HEPHL1 is classified as a druggable target (Druggable Genome category) with score 0.0.

Genetic testing for HEPHL1 is available. Testing is considered research-grade for diagnosis.

Phenotype severity distribution: 28 always present features, 8 very common features, 2 common features.

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