In the case of SLE, the group found widespread changes in DNA methylation status at a significant number of genes. Dr. Esteban Ballestar, senior author of the study, noted that this is the largest number of genes exhibiting DNA methylation changes observed in an autoimmune disease to date, and includes genes previously implicated in SLE pathogenesis. Importantly, Ballestar's team found that a significant number of the novel differentially methylated genes are related to multiple immune system functions and are potentially linked to SLE.

"Our study suggests that the effect of the environment or differences in lifestyle may leave a molecular mark in key genes for immune function that contributes to the differential onset of the disease in twins," Ballestar said. Most studies of DNA methylation and human disease have been in the context of cancer research, Ballestar noted, and he hopes that this work will attract more researchers to also investigate DNA methylation alterations in autoimmune disease and other disorders for the development of therapies.

Source: Cold Spring Harbor Laboratory