Keratin, type I cytoskeletal 16 (cytokeratin-16) Keratin 16 is e, Xenopus/Amphibian,pressed in keratinocytes, which are undergoing rapid turnover in the suprabasal region (also known as hyperproliferation-related keratins). Defects in cytokeratin-16 are a cause of pachyonychia congenita type 1 (PC1), also known as Jadassohn-Lewandowsky syndrome. PC1 is an autosomal dominant ectodermal dysplasia characterized by hypertrophic nail dystrophy resulting in onchyogryposis (thickening and increase in curvature of the nail),Porcinealmoplantar keratoderma, follicular hyperkeratosis, and oral leukokeratosis.