IGF2 and Beckwith-Wiedemann syndrome: In contrast, gain of methylation at the maternal H19-ICR (H19-ICR GOM) causes biallelic expression of IGF2 and repression of H19. This leads to Beckwith-Wiedemann syndrome (BWS; OMIM 130650), an overgrowth disorder characterized by macroglossia, macrosomia, abdominal wall defects, and childhood cancers such as Wilms tumor8.