In comparison to girls, autism is majorly diagnosed among boys, finds a study published in the journal Molecular Autism. As per the researchers from the Stanford University School of Medicine, it might be due to the brain differences between girls and boys.

Study's lead researcher Kaustubh Supekar said girls having autism show less severe repetitive/restrictive behaviors. This raises a possibility that girls having less severe repetitive and restrictive behaviors are not tested for autism or the diagnosis is misclassified as social communication disorder.

Supekar added, "On the other hand, boys with more pronounced repetitive and restrictive behaviors may show more false positives for autism spectrum disorders, given that repetitive and restricted behaviors are not specific to children with autism and are also observed in other neurodevelopmental disorders".

In the research, the researchers included 128 ASD girls and 618 ASD boys. The researchers wanted to know which specific signs of autism show significant gender differences and also how girl's brain differ from that of boys.

The researchers said both the groups were in similar age and IQ. The researchers said girls and boys diagnosed with autism behave differently. Autism's symptoms include impaired social interaction, verbal and non-verbal communication and restricted and repetitive behaviors.

In the next stage, the researchers have evaluated data from the Autism Brain Imaging Data Exchange including structural MRI brain scans of 25 boys and 25 girls having autism and 19 boys and 19 girls. The researchers think that girls with autism may not display the disorder in less severe ways than males.