Robin sequence with facial and digital anomalies in two half-brothers by the same mother.

Two half-brothers by the same mother presented with the Robin sequence and facial and digital anomalies. The mother has a normal face and mild hyperopia without abnormality on radiographs of the hands, feet, and pelvis. The older son is 4 years and the younger is 6 months old. Both have normal psychomotor development. To the best of our knowledge this familial association has not been reported before and probably represents a previously unrecognized heritable malformation syndrome. The occurrence of the syndrome in 2 half-brothers by the same unaffected mother suggests X-linked recessive inheritance.