In Beckwith-Wiedemann Syndrome (BWS) the loss of methylation (LOM) at the KCNQ1OT1 on chromosome 11p15.5 (within imprinting center 2 [IC2]) is maternally imprinted and represents the cause in 50–60% of patients. Here, KCNQ1OT1 is linked to Beckwith-Wiedemann syndrome.