A recent paper indicates that boys are more at risk than girls owing to the fact that “males who carry specific genetic alterations on their X-chromosome have an elevated risk for developing autism spectrum disorder, or ASD.”

It goes on to say…

Boys inherit one X-chromosome from their mother and one Y-chromosome from their father, explained Scherer. “If a boy’s X-chromosome is missing the PTCHD1 gene or other nearby DNA sequences, they will be at high risk of developing ASD or intellectual disability.

“Girls are different in that, even if they are missing one PTCHD1 gene, by nature they always carry a second X-chromosome, shielding them from ASD. While these women are protected, autism could appear in future generations of boys in their families.”