When the article “You Can Hurry Science” was published in Proto (Winter 2006), researchers knew that autism, a neurodevelopmental disorder affecting as many as one in 166 children, had complex genetic causes. Those factors were known in fewer than 10% of cases, and they were associated with other disorders. But in February, two research groups independently reported the first strong genetic cause to be specifically associated with autism: a variation on chromosome 16 that often arises spontaneously and accounts for about 1% of cases.

One percent seems meager, says Mark Daly at the Center for Human Genetic Research of the Massachusetts General Hospital, who is senior author of one of the studies, but in fact the variation opens the door to understanding autism’s underlying biological pathways. As researchers drill down to find the gene responsible, he says, they can begin as well to connect the dots to other genes that share the same pathways and thus might also play a role in autism. And Children’s Hospital Boston is already developing a diagnostic test to spot the chromosome 16 variation.

University of Chicago researchers, who published their results in the journal Human Molecular Genetics, studied 712 subjects, whereas members of the Autism Consortium in Boston, whose results appeared in the New England Journal of Medicine, scanned the DNA of more than 2,000 subjects in three different populations. Both groups were able to make such strides because they could process data more quickly than ever—the latest generation of gene chips can analyze more than a million genetic variations in patients—and because they were more willing to band together across institutions to share information.

That’s some consolation for Portia Iversen, who, with her husband, Jon Shestack, founded the Autism Genetic Resource Exchange, upon which both research groups relied for samples. “There’s such an abundance of data now that everybody’s scrambling,” she says, a very different picture from when their son Dov (above) was diagnosed in 1994. Dov, now 15, can communicate through typing and is beginning to talk. “There are better minutes and worse minutes,” Iversen says. “But for him, he’s doing really well.”