Holt-Oram syndrome (HOS) is the most common form of heart-hand syndrome and is characterized by skeletal abnormalities of the upper limbs and mild-to-severe congenital cardiac defects. The disease is MONDO_0007732 (Holt-Oram syndrome). Also known as: HOLT-Oram syndrome, HOS, Holt Oram Syndrome, atriodigital dysplasia type 1, heart-hand syndrome type 1.