Although nails appear normal at birth, dystrophic changes develop within the first decade of life, resulting in onycholysis of fingernails and anonychia of toenails (summary by Rafiq et al., 2004). This disorder is referred to here as nonsyndromic congenital nail disorder-9 (NDNC9). For a list of other nonsyndromic congenital nail disorders and a discussion of genetic heterogeneity, see NDNC1 (161050). [from OMIM]