MONDO_0018633 (20q11.2 microdeletion syndrome) is a rare, genetic, syndromic intellectual disability characterized by psychomotor delay, hypotonia, feeding difficulties, failure to thrive, anomalies of the hands and feet (clinodactyly, camptodactyly, brachydactyly, feet malposition), and craniofacial dysmorphism. Associated prenatal growth retardation, and gastrointestinal, heart and eye anomalies have been reported. Also known as: Del(20)(q11.2), monosomy 20q11.