A simple genetic test could be the key to identifying autism in children even earlier, and the Medical University of South Carolina has been named one of the sites this week in a national study testing this theory.

Across the country, 660 children — at least 50 of them locally — will undergo blood work for the study. Researchers are trying determine if amount of RNA replicated in a child’s genes can be an early indicator of autism, which affects about one in one in 88 children in the U.S., according to SynapDx Corp., the organization financing the study. It’s more prevalent in boys — one in 54 is diagnosed with a developmental disorder in the autism spectrum. Children can exhibit symptoms as early as 18 months, but the average diagnosis is around 4.

Dr. Michelle Macias, an MUSC pediatrician and the lead investigator for the study at MUSC, said the test isn’t meant to replace a traditional diagnosis but could prove an effective tool for clinicians.

“We know there’s got to be a better way to help identify children earlier with development disorders,” Macias said. “The earlier it’s detected, the better the outcome because we can start earlier intervention.”

There’s already a waiting list to participate, but researchers are still accepting referrals from primary care physicians for children between 18 months and 5 years old with development disorders.

MUSC also has partnered with public schools in Charleston, Berkeley and Dorchester counties for a separate autism study.