Prenatal diagnosis of the Beckwith-Wiedemann syndrome

We report on the prenatal diagnosis of Beckwith-Wiedemann syndrome (BWS) in a pregnancy monitored because of a previously affected child. The proposita had classical stigmata of BWS including macroglossia, omphalocele, and typical ear creases. Chromosomes were 46,XX. Both parents and the extended maternal family were clinically normal. In a subsequent pregnancy by another father, the mother had serial ultrasound monitoring at 13.5, 18, and 19 weeks gestation which showed an enlarged abdominal circumference and a 2-cm omphalocele. At termination the female fetus weighed more than two times the expected weight, had striking hypertrophy of skeletal muscles, a protuberant abdomen, and a 2-cm omphalocele and characteristic facial appearance. Autopsy confirmed generalized organomegaly. This is the first report of the prenatal diagnosis of BWS prior to 20 weeks in an at-risk family. The recurrence in this family emphasizes the difficulty in providing accurate genetic recurrence risks in BWS and suggests that ultrasonographic prenatal diagnosis should be offered to families even when the case appears to be "sporadic."