Boys at higher risk of autism than girls

New Delhi: Autism spectrum disorders (ASD) are more prevalent among boys than girls, says a study.

Scientists say that they have discovered differences in a brain signalling pathway that causes more boys to be autistic than girls.

"One intriguing aspect of autism is that it predominantly affects males; four boys are affected for every one girl," said Ted Abel, from the University of Iowa in the US.

"We don't understand what it is about this disorder that predisposes boys as compared to girls to develop autism," said Abel.

This male bias is also seen in other neurodevelopmental disorders, like attention deficit hyperactivity disorder (ADHD) and specific language impairments.

Nearly one in every 200 cases of autism is caused by the deletion of a section of DNA on a particular chromosome.

This type of disorder is also known as a copy number variation (CNV).