Pachyonychia congenita type 2 (Jackson-Lawler syndrome) or PC-17: case report.

摘要: Pachyonychia congenita (PC) is a rare genodermatosis caused by mutations in any of the four genes KRT6A, KRT6B, KRT16, or KRT17, which can lead to dystrophic, thickened nails and focal palmoplantar keratoderma, among other manifestations. Although classically subdivided into two major variants, PC-1 (Jadassohn-Lewandowski syndrome) PC-2 (Jackson-Lawler syndrome), according localization KRT6A/KRT16 KRT6B/KRT17 genes, respectively, classification system based on mutant gene (PC-6a, PC-6b, PC-16 PC-17) has been recently proposed. We report 2-year-old female patient with history discolored nails, small cystic papulonodules central face, dry, unruly curly hair, slight hyperkeratosis, natal teeth. Both her father paternal grandfather presented onychodystrophy, previous excision "sebaceous" cysts. Molecular genetic analysis revealed missense mutation (c.1163T>C) heterozygosity exon 6 KRT17 gene, confirming diagnosis type), PC-17. conclude that PC relatively easy consistent clinical diagnosis, but high index suspicion required if be made correctly. With this case, authors intend draw attention condition role dermatologist diagnosis.