MONDO_0017928 (9p13 microdeletion syndrome) is a rare chromosomal anomaly syndrome, resulting from a partial interstitial deletion of the short arm of chromosome 9, characterized by mild to moderate developmental delay, hand tremors, myoclonic jerks, attention deficit-hyperactivity disorder and a social personality. Patients also present bruxism, short stature and minor facial dysmorphic features (e.g., bilateral epicantic folds, broad, flat nasal bridge, anteverted nares, low-set ears micro/retro-gnathia). Also known as: Del(9)(p13), monosomy 9p13.