Variability of expression of the orofaciodigital syndrome type I in black females: six cases.

Orofaciodigital syndrome type I (OFD I) includes striking orodental, facial, digital, renal, and central nervous system (CNS) abnormalities. Frequently associated with mental retardation, OFD I is inherited as an X-linked dominant trait, lethal in males. Here, we report the variable expressivity of OFD I in 6 black U.S. females and review findings in 2 previously reported black patients. Only these 8 of over 160 reported cases involve blacks. Abnormalities observed in black patients are similar to those observed in whites, but with specific differences. Only 25% of the blacks had cleft palate and none was observed with midline cleft of the upper lip. Among whites, 80% have cleft palate and 45% midline cleft of the upper lip. These findings suggest that racial genetic factors may protect lip and palate development in blacks, even in the presence of the OFD I gene. CNS abnormalities, including agenesis of the corpus callosum, hydrocephaly, cystic brain lesions, seizures, and mental retardation, were present in 50% of our the cases. This figure is greater than previously reported. Polycystic kidneys were present in 3 of our patients. Including a previously reported patient, 50% of the black OFD I patients show polycystic kidneys. Hyperplastic and supernumerary frenula, with or without brachydactyly, have been shown to be strong diagnostic criteria in our patients. New findings reported here include intracranial berry aneurysm, periodontal disease, and lip pits. Clinicians treating these patients should be aware of the pleiotropic manifestations of the syndrome, which may include renal and CNS anomalies. Ultrasonic and computed tomography scan studies are indicated in patients diagnosed with OFD I.