A novel mutation of keratin 17 gene in a pedigree with pachyonychia congenita type 2

摘要

Pachyonychia congenita (PC) is a group of autosomal dominant skin disorders characterized by hypertrophic nail dystrophy. There are two main clinical subtypes of PC: type i (PC-i) (Jadassohn-Lewandowsky syndrome), and type 2 (PC-2) (Jackson-Lawler syndrome). PC-2 is readily differentiated from PC-i by multiple steatocysts and/or natal teeth and is caused by mutations in keratin 17 or keratin 6b.Here, we report a novel mutation in a Chinese pedigree of PC-2 with typical clinical presentations and an autosomal dominant inheritance pattern (Fig. 1).The proband was a 30-year-old man, who had been born with natal teeth and who had developed thickened toenails and fingernails of a yellow-grayish color by the age of one year. He had suffered recurrent blistering on the feet after long periods of walking, followed by gradual thickening of the plantar keratoderma. Multiple pilosebaceous cysts presented all over his body at puberty. No hair abnormality was observed.