_:vb50940350 . _:vb50940350 . _:vb50940350 "url:https://ghr.nlm.nih.gov/condition/anonychia-congenita"^^ . _:vb50940350 "url:https://pubmed.ncbi.nlm.nih.gov/26149975/"^^ . _:vb50940350 . _:vb50940350 "A nonsyndromic congenital nail disorder that is characterized by complete absence or severe hypoplasia of all fingernails and toenails without significant bone anomalies, and that has_material_basis_in homozygous or compound heterozygous mutation in the R-spondin-4 gene on chromosome 20p13."^^ . _:vb50940350 . _:vb50940350 .