Mutations of KRT6A are more frequent than those of KRT16 in pachyonychia congenita type 1: report of a novel and a recently reported mutation in two unrelated Chinese families.

摘要

Sir, Keratins are structural proteins of epithelial tissue that consist of four helical segments named 1A, 1B, 2A and 2B. Mutations at the beginning of helix 1A and the end of helix 2B can lead to different epithelial disorders.Pachyonychia congenita (PC) is an autosomal dominant disorder characterized by hypertrophic nail dystrophy. In type 1 (MIM 167200), oral leucokeratosis, palmoplantar keratoderma and follicular keratosis may be observed. Type 2 (MIM 167210) has the useful distinguishing feature of sebaceous cysts which normally develop around puberty. As is known, keratin 6A (KRT6A) or keratin 16 (KRT16) defects cause PC-1, and mutations in keratin 6B (KRT6B) or keratin 17 (KRT17) cause PC-2. Here, we report a novel mutation (Y46SH) of KRT6A in a Chinese pedigree and a recently reported mutation (N171D) in a Chinese sporadic case of PC-1.