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Mutations in KAT6B cause Genitopatellar syndrome (a condition with genital anomalies and hypoplasia of the patellae) and Ohdo syndrome, SBBYS variant (a condition with blepharophimosis). This website provides links to further information on KAT6B for clinicians, scientists, and families.

Both syndromes share global developmental delay or intellectual disability, hypotonia, cryptorchidism in males and small or absent patellae. Heart defects, abnormal teeth, deafness, and thyroid problems are common to both syndrome. Flexion contractures of the hips and knees, club feet, agenesis of the corpus callosum with microcephaly, and hydronephrosis and multiple renal cysts can be seen in Genitopatellar syndrome. Lower extremity joint stiffness, long thumbs/great toes, immobile mask-like face, blepharophimosis or ptosis, and lacrimal duct anomalies are observed in Ohdo syndrome, SBBYS variant. The conditions are caused by de novo (not present in parents) dominant mutations (only one of the two copies of the gene needs to be mutated). The risk for subsequent pregnancies is thus about 1% if the mutation is not found in the parental blood. Children of affected individuals have a 50% chance of being affected. Treatment of manifestations include speech therapy, orthopedic interventions as needed and physical therapy to help increase joint mobility. In the presence of cryptorchidism, congenital heart defects, dental anomalies, hearing loss, thyroid problems, or ophthalmologic findings, routine management of these issues is recommended. Surveillance includes following developmental progress, contractures, scoliosis, ophthalmologic problems, thyroid function, heart defects, and kidneys by appropriate specialists if anomalies are present.