A new technique can simultaneously sequence DNA and pinpointsome of the chemical modifications that turn genes on or off, according to a report published 9 May in Nature Methods.In particular, the technique reveals methyl groups bound to DNA bases. DNA methylation — one of several types of 'epigenetic' changes — allows organisms to express genes at various times, and in different tissues, without changing the underlying DNA code.Epigenetic changes, which are influenced by environmental factors such as diet, may be important in autism. Candidate genes account for less than 10 percent of all cases of the disorder."Epigenetics is that extra layer on top of the genetic code," says Janine LaSalle, professor of medical microbiology and immunology at the University of California, Davis. "For a complex disorder like autism that's a combination of multiple genetic risk factors and environmental risk factors, epigenetics is right there where the action is."Read more at...SFARI, May 2010.