Microdeletions/duplications or point mutations at the ICRs are usually found in familial BWS with aberrant 11p15 methylation; for example, deletions and point mutations of OCT4/SOX4 binding sites in H19/IGF2: IG DMR are associated with H19/IGF2: IG DMR hypermethylation [5, 35, 36]. Here, POU5F1 is linked to Beckwith-Wiedemann syndrome.