BWS is an imprinting disorder associated with genetic and epigenetic defects affecting imprinted growth regulatory genes, IGF2/H19 and CDKN1C/KCNQ1OT1, that are located on chromosome 11p15.5 and independently regulated through methylation of two imprinting control regions (IC1 and IC2) [2]. Here, CDKN1C is linked to Beckwith-Wiedemann syndrome.