thumb deformity-alopecia-pigmentation anomaly syndrome (Monarch Disease Ontology term MONDO_0008562) is a rare, genetic, congenital limb malformation syndrome characterized by short stature, sparse scalp hair, hypoplastic, proximally-placed thumbs, and skin hyperpigmentation with areas of 'raindrop' depigmentation. Presence of a single, upper central incisor has also been reported. There have been no further descriptions in the literature since 1988. Also known as: thumb deformity and alopecia.