A syndrome characterized by abnormal development of the face, skin and genitals. Clinical expressions of the disease include cleft lip, with or without cleft palate, contractures of the lower extremities, abnormal external genitalia, syndactyly of fingers and/or toes, and a pyramidal skin fold over the hallux nail. It has_material_basis_in mutations in the IRF6 gene on chromosome 1. [ http://purl.obolibrary.org/obo/ECO_0007638 http://purl.obolibrary.org/obo/ECO_0007637 http://purl.obolibrary.org/obo/ECO_0007645 ]