An online project aims to gather DNA and other information from 50,000 people with autism and their family members.

Though the cause of the social communication disorder is unknown and believed to be a mix of environmental and genetic factors, scientists have identified 50 to 70 genes that may play a role in the condition. Some estimate that a total of 350 or more could be involved.

The long-term study involves researchers from more than 21 medical institutions; find information at

Autism diagnoses have risen in the United States at a high pace, and a survey this year estimated that one out of 45 children age 3 to 17 has the condition.

There is no blood test or other biomarker for the condition, so doctors rely on parent and teacher surveys, observations and a test that simulates how the person might respond in a typical conversation. With the complexity and diversity of autism, individualized treatments are necessary, but it's unclear what role genes will play in determining which ones will work. - Washington Post