Maria H. Milekic, Ph.D., of the Research Foundation for Mental Hygiene, New York State Psychiatric Institute/Columbia University, will investigate a possible mechanism to explain findings that suggest that fathers over 40 years of age pose an increased risk for autism spectrum disorders in their children. The role of epigenetics may be an important factor. Epigenetics involves mechanisms such as DNA methylation in which the chemical methyl is added to a gene's DNA to change the way the gene is expressed. DNA methylation during production of new sperm is an active process, susceptible to errors that can be propagated to subsequent generations. To test whether the effects of paternal age on autism is due to epigenetic mechanisms, Dr. Milekic and her team have developed an animal model in which to compare methylation changes in the offspring of old and young fathers.