- girls may not be diagnosed with autism as frequently as boys because their symptoms may be different
- treatment for girls with autism may need to be different than what is used for boys
One study used eye tracking technology to compare social interaction in boys and girls. This study found that girls and boys with autism interact with their "social environment" differently.(Source)
Another study compared the genes of girls and boys with autism and found differences in their genetic samples. One of the researchers commented "to develop autism in a girl requires more genetic mutations.” The type of mutations they found are called “de novo” mutations which means that the genetic change occurs in the sperm or the egg. It isn't a gene that’s passed down from the parents. These mutations can occur randomly, or they can be caused by an environmental trigger." (Source)
These studies are preliminary and more research is planned.