Genetic Defects of Nails and Nail Growth

Abstract Several genetic disorders manifest with nail dystrophy, allowing diagnosis and clues to seeking manifestations beyond the nail changes. Pachyonychia congenita results from abnormalities in one of five different keratin genes and can lead to exquisite pain on walking because of plantar foot involvement. Dyskeratosis congenita is a group of disorders with telomere shortening that often manifests with early oral and nail abnormalities, particularly dorsal pterygium. Dyskeratosis congenita is complex, with life‐threatening potential manifestations related to the development of squamous cell carcinoma, bone marrow failure and pulmonary fibrosis. Nail–patella syndrome has characteristic marked hypoplasia or anonychia of the nails, especially the thumbs, and should prompt investigation of the associated bone abnormalities. Hereditary anonychia can also be an isolated finding.