Pachyonychia Congenita Type PC-K6a: The first report in the Vietnamese population

Abstract

Background: Pachyonychia congenita (PC) comprises a group of rare autosomal dominant genetic disorders. It is characterized by hypertrophic nail dystrophy, focal palmoplantar keratoderma, follicular keratosis, and oral leukokeratosis. It is associated with mutations in five differentiationspecific keratin genes: KRT6A, KRT6B, KRT6C, KRT16, or KRT17. The case is being reported for its rarity. To the best of our knowledge, this is the first report of PC, from Vietnam, confirmed by genetic analysis.

Case presentation: A four-year-old Vietnamese girl presented with a thickened nail and oral leukokeratosis soon after birth. She was diagnosed with onychomycosis and chronic oral candidiasis and was treated with systemic anti-fungals in children's hospitals and dermatology departments multiple times; however, no treatments were effective. In collaboration with the International Pachyonychia Congenita Research Registry (IPCRR), the clinical features were consistent with a diagnosis of PC type PC-K6a. The genetic testing, performed through the IPCRR, shows a K6a N171K mutation.

Conclusions: The IPCRR helps screen PC's clinical features and confirm a diagnosis at the molecular level, which is beneficial and crucial for validating the condition's clinical impression.