New research adds to the theory that girls are more naturally protected than boys from developing autism and other developmental disorders.
While a small number of genetic mutations seem to be enough to manifest symptoms in boys, a new study published Thursday in the American Journal of Human Genetics suggests that far more extreme genetic anomalies must be present in girls to warrant a diagnosis.
The finding could help explain why autism is nearly five times more common in boys.
“This is the first study that convincingly demonstrates a difference at the molecular level between boys and girls referred to the clinic for a developmental disability,” said Sébastien Jacquemont of the University Hospital of Lausanne in Switzerland, the study’s lead author. “The study suggests that there is a different level of robustness in brain development, and females seem to have a clear advantage.”
For the study, researchers looked at DNA samples from more than 16,000 people with autism and other neurodevelopmental disorders. They found that girls with the conditions had a greater number of harmful variations in their genes than did boys with the same diagnosis.
“Overall, females function a lot better than males with a similar mutation affecting brain development,” Jacquemont said.
Researchers said the findings could help bring about more gender-specific diagnosis and screening methods.