Other reported malformations include pseudocleft of the upper lip (resembling a surgically repaired cleft or a fused cleft), malformed ears, conduction or sensorineural deafness, pre-auricular pits, lip pits, highly arched palate, dental anomalies, ocular anomalies (coloboma, microphthalmia), and subcutaneous cysts of the scalp. Premature greying of the hair occurs in affected adults. One patient had, in addition to the typical features of BOFS, partial agenesis of the cerebellar vermis, while two sibs with this syndrome also had orbital hemangiomatous cysts. Urologic examination may reveal kidney abnormalities (agenesis, cysts, hydronephrosis). Preaxial polydactyly and white forelock were described in two cases of BOFS. Intelligence is normal, but speech is hypernasal. Growth continues after birth, but stays between the third and fifth percentile. Postauricular cervical branchial defects are among the most constant features of the syndrome, and pathological findings of the excised branchial defects showed thymic remnants in several cases.
BOFS is caused by mutations involving the gene TFAP2A (transcription factor AP-2 alpha; 6p24).
