Researchers are recruiting autistic children for a study that will test whether injecting stem cells banked from their umbilical cords can lessen symptoms and provide insights into the nature of the disorder. While stem cells have been promoted, and sold, as a treatment for autism, few clinical trials have been conducted to see whether they’re effective. The study, which begins enrolling patients today, is the first of its kind approved by the U.S. Food and Drug Administration to assess the use of stem cells as a potential autism therapy, said Michael Chez, director of pediatric neurology at Sutter Medical Center in Sacramento, California, and the principal investigator.