KCNQ1 and Beckwith-Wiedemann syndrome: The IC1 (H19/IGF2:IG DMR) regulates the expression of the H19 and IGF2 genes, while the expression of CDKN1C, KCNQ10T1 and KCNQ1 is under the control of IC2 (KCNQ1OT1:TSS DMR).1 The term Beckwith-Wiedemann spectrum (BWSp) describes “classical BWS without a molecular diagnosis and BWS-related phenotypes with an 11p15.5 molecular anomaly”.1