Japanese and North American/European patients with Beckwith-Wiedemann syndrome have different frequencies of some epigenetic and genetic alterations.

Beckwith-Wiedemann syndrome (BWS) is an imprinting-related human disease. The frequencies of causative alterations such as loss of methylation (LOM) of KvDMR1, hypermethylation of H19-DMR, paternal uniparental disomy, CDKN1C gene mutation, and chromosome abnormality have been described for North American and European patients, but the corresponding frequencies in Japanese patients have not been measured to date. Analysis of 47 Japanese cases of BWS revealed a significantly lower frequency of H19-DMR hypermethylation and a higher frequency of chromosome abnormality than in North American and European patients. These results suggest that susceptibility to epigenetic and genetic alterations differs between the two groups.