In a recent paper published in the New England Journal of Medicine, a group of Boston Autism Consortium members reported a significant breakthrough in the search for genetic links to autism. They have discovered that a rare mutation—involving the deletion or duplication of 25 genes on chromosome 16—accounts for just over 1 percent of autism cases in the United States. Although this mutation explains only a small portion of the disease, researchers are confident that similar findings will soon follow. As Susan Santangelo, one of the paper’s authors, explains: “If we can isolate the genes involved, it may give us a more accurate view of the underlying pathophysiology and direct us toward other similar genes or other genes in the same pathway.” Additional background information is available at the HarvardScience website. For information on the Boston Autism Consortium and Susan Santangelo, see “Beyond the Genome,” in the January-February 2008 issue of Harvard Magazine, and the cover article, “A Spectrum of Disorders.”