Global DNA methylation levels in repetitive DNA sequences can be detected by restriction digestion using methylation-sensitive endonucleases (eg, MspI cuts 5′-CCGG-3′ independently of the methylation status of the sequence, while cutting of 5′-CCGG-3′ by HpaII depends on the methylation status of the sequence).47 Considering the high abundance of DNA repetitive elements such as the long interspersed nuclear element 1 (LINE-1) and the Alu sequence in the genome,48 levels of global DNA methylation can also be estimated by the methylation status of DNA repetitive elements.49 We identified six studies that examined AUD-or alcohol consumption-associated global DNA methylation changes in repetitive DNA sequences (Table 1).
