The Hammetts smooth out stray strands of hair on Francis' head. Meredith Rizzo/NPR hide caption

toggle caption Meredith Rizzo/NPR

The Centers for Disease Control and Prevention estimates that 1 in 68 children has an autism spectrum disorder. Kelvin Murray/Getty Images hide caption

toggle caption Kelvin Murray/Getty Images

Jonathan Keleher talks with a colleague, Rafael Wainhaus, at work. Keleher was born without a cerebellum, but his brain has developed work-arounds for solving problems of balance and abstract thought. Ellen Webber for NPR hide caption

toggle caption Ellen Webber for NPR

One Saturday each month, the Pacific Science Center of Seattle opens early for people with autism spectrum disorders. John Keatley/Pacific Science Center hide caption

toggle caption John Keatley/Pacific Science Center

Katie Clapp shares a laugh with her son Andy Tranfaglia, 25, at their home in West Newbury, Mass. Andy has a rare genetic condition called fragile X syndrome. Ellen Webber for NPR hide caption

toggle caption Ellen Webber for NPR

Police officers and other first responders attend a 2012 autism information training session in Wrentham, Mass. Several cities are working to reduce the risk of miscommunication between police officers and people with autism. Elise Amendola/AP hide caption

toggle caption Elise Amendola/AP

Images of the developing fetal brain show connections among brain regions. Allen Institute for Brain Science; Bruce Fischl, Martinos Center for Biomedical Imaging, Massachusetts General Hospital hide caption

toggle caption Allen Institute for Brain Science; Bruce Fischl, Martinos Center for Biomedical Imaging, Massachusetts General Hospital

Researchers say intervention in early childhood may help the developing brain compensate by rewiring to work around the trouble spots. iStockphoto hide caption

toggle caption iStockphoto

Clinical specialist Catey Funaiock took notes while observing a 5-year-old boy at the Marcus Autism Center, part of Children's Healthcare of Atlanta, in September. David Goldman/AP hide caption

toggle caption David Goldman/AP