Loss of methylation at DMR2 (KCNQ1OT1 hypomethylation), is the most frequent alteration, in around 50% of BWS patients [194] whereas loss of methylation at DMR1 (H19 hypomethylation) is typically observed in SRS is found in around 40% of SRS patients [192,195]. The gene discussed is KCNQ1OT1; the disease is Silver-Russell syndrome.