20p13 microdeletion syndrome (MONDO_0017780) is a rare chromosomal anomaly characterized by developmental delay, mild to moderate intellectual disability, epilepsy, and unspecific dysmorphic signs. High palate, delayed permanent tooth eruption, hypoplastic fingernails, clinodactyly and short fingers have also been reported. Also known as: 20p subtelomeric deletion syndrome, Del(20)(p13), monosomy 20p13.