Loss-of-function mutations in patatin-like phospholipase domain-containing protein 1 (PNPLA1) cause autosomal recessive congenital ichthyosis, and altered PNPLA1 activity is implicated in the pathogenesis of atopic dermatitis and other common skin diseases. The gene discussed is PNPLA1; the disease is autosomal recessive congenital ichthyosis.