Features include always present findings: Absent eyebrow, Absent eyelashes, Small nail, and Absent hair and others; and common findings: Inguinal hernia, Unilateral cryptorchidism, and Onycholysis of fingernails. 18 total HPO annotations.

HOXC13 encodes homeobox C13 (330 aa). Transcription factor which plays a role in hair follicle differentiation. Regulates FOXQ1 expression and that of other hair-specific genes Highest expression in Skin Sun Exposed Lower leg (12.9 TPM) and Skin Not Sun Exposed Suprapubic (10.1 TPM).

Ectodermal dysplasia 9, hair/nail type is associated with mutations in the HOXC13 gene on chromosome 12.

HOXC13 is classified as a druggable target (Clinically Actionable and Transcription Factor categories) with score 52.2.

Genetic testing for HOXC13 is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 7 always present features, 3 common features.

No clinical trials have been registered for ectodermal dysplasia 9, hair/nail type.

3 publications have been identified in PubMed for ectodermal dysplasia 9, hair/nail type. Research spans Case Report / Case Series (33%), Basic Science / Preclinical (33%), and Epidemiology / Natural History (33%).

Recent Publications

• Kovalskaia VA (2026). [PMID: 41645317](https://pubmed.ncbi.nlm.nih.gov/41645317/). *Orphanet J Rare Dis*. [Epidemiology / Natural History]

• Sharma A (2026). [PMID: 41714886](https://pubmed.ncbi.nlm.nih.gov/41714886/). *Pediatr Dermatol*. [Case Report / Case Series]

• Clowes V (2024). [PMID: 40225922](https://pubmed.ncbi.nlm.nih.gov/40225922/). *Hum Mutat*. [Basic Science / Preclinical]