Mondo Description Coffin-Siris syndrome (CSS) is a rare congenital multi-systemic genetic disorder characterized by aplasia or hypoplasia of the distal phalanx or nail of the fifth digit, developmental delay, intellectual disability, coarse facial features, and other variable clinical manifestations.

Disease Ontology Description An autosomal dominant non-syndromic intellectual disability that is characterized by mental retardation associated with coarse facial features, hypertrichosis, sparse scalp hair, and hypoplastic or absent fifth fingernails or toenails.