Histone acetyltransferase which may be involved in both positive and negative regulation of transcription. Required for RUNX2-dependent transcriptional activation. May be involved in cerebral cortex development. Component of the MOZ/MORF complex which has a histone H3 acetyltransferase activity. A chromosomal aberration involving KAT6B may be a cause acute myeloid leukemias. Translocation t(10;16)(q22;p13) with CREBBP. Defects in KAT6B are a cause of Ohdo syndrome, SBBYS variant (SBBYSS). SBBYSS is a syndrome characterized by distinctive facial appearance with severe blepharophimosis, an immobile mask-like face, a bulbous nasal tip, and a small mouth with a thin upper lip. The condition presents in infancy with severe hypotonia and feeding problems. Associated skeletal problems include joint laxity, abnormally long thumbs and great toes, and dislocated or hypoplastic patellae. Structural cardiac defects are present in around 50% of cases, and dental anomalies, including small and pointed teeth, are common. Many affected individuals have abnormalities of thyroid structure or function. SBBYSS is usually associated with severe mental retardation, delayed motor milestones, and significantly impaired speech. Defects in KAT6B are a cause of genitopatellar syndrome (GTPTS). GTPTS is a rare disorder consisting of microcephaly, severe psychomotor retardation, and characteristic coarse facial features, including broad nose and small or retracted chin, associated with congenital flexion contractures of the lower extremities, abnormal or missing patellae, and urogenital anomalies. Belongs to the MYST (SAS/MOZ) family. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.