The cancer risk in KCNQ1 deletion cases of BWS is presently unknown due to the low number of affected individuals however BWS patients with isolated loss of methylation within IC2 are at risk for hepatoblastoma and other tumours including rhabdomyosarcoma, gonadoblastoma and thyroid carcinoma [6]. Here, KCNQ1 is linked to Beckwith-Wiedemann syndrome.