some llp15.3-.pter and monosomic for chromosome 5p15.3-.pter (karyotype 46,XY,der(5)t(5;ll)(pl5.3;pl5.3)pat). Paternally derived duplications of llpl5.5 are associated with Beckwith-Wiedemann syndrome (BWS) and both family members trisomic for llpl5.5 had prenatal overgrowth (birth weights >97th centile), macroglossia, coarse facial features, and broad hands. We review the clinical features of ...