CDKN1C and Beckwith-Wiedemann syndrome: It is an imprinting disorder caused by diverse genetic and epigenetic defects within the two imprinting centers (IC1, IC2) in 11p15.5 encompassing the coding genes IGF2, H19, CDKN1C and KCNQ1. In 5% of sporadic and 20% of familial BWS cases, genomic CDKN1C variants are detected that are distributed over the whole coding region and are predicted to cause loss of function [2].