In a video from the website InteractingWithAutism.com, 11-year-old Keena Ballard is an outspoken advocate for autism research and care. Her mother described the early signs she saw in her daughter.
"She was a very rigid child. She lined up all her toys. Low eye contact," said Kameena Ballard, Keena's mother.
Early intervention helped Keena blossom. But many parents like Kameena would like to learn more about what causes autism.
Researchers have long known that air pollution can increase a child's risk. And kids who carry a specific genetic disposition, something called the MET gene, are also more likely to have autism. Now, for the first time, scientists say the two together appear to triple a child's autism risk.
"By seeing how these work together, hopefully it will provide us some insight into what specifically makes both this gene and this environmental exposure increase risk for autism," said Dr. Heather Volk, an environmental neurodevelopmental disorders researcher at Children's Hospital Los Angeles.
Sixty percent of children with autism have the MET gene. So what about the other 40 percent? Researchers believe other environmental factors may also be involved. So these findings are just the beginning of solving the mystery of what causes autism.
"We're hoping that by potentially identifying two that work together, that can make it easier for us to identify other pieces that fit together," said Volk.
Until researchers learn more, Volk recommends expectant moms limit outdoor activity on high-pollution days.
Parents like Kameena are grateful that scientists are finding more pieces to the puzzle.
"The earlier we have some sort of indication of what's going on with these children, the harder that we can fight and advocate for them," Kameena said.
Dr. Volk and her colleagues plan to do more research to find out more about the biological connection between air pollution and the MET gene, which she believes will lead to better treatments.