Abnormality of chromosome 11 in patients with features of Beckwith-Wiedemann syndrome.

Two unrelated children with features of Beckwith-Wiedemann syndrome have been found to have partial duplication of chromosome 11p. A review of six other reported cases of partial duplication of 11 p revealed features of this syndrome not previously recognized. We suggest that karyotype studies with banding techniques should be done in children with features of Beckwith-Wiedemann syndrome and developmental delay or retardation.