DNA discovery offers clues to understanding male autism

Research into the DNA of autism spectrum disorder (ASD) sufferers has uncovered indications as to why the condition is far more likely to affect boys than girls.

The Centre for Addiction and Mental Health and the Hospital for Sick Children (SickKids) in Toronto have found that mutations in a certain gene in the single X chromosome possessed by males greatly increases the chances of developing ASD.

Girls are thought to be unaffected by this variation in the PTCHD1 gene, due to the fact females carry a second X chromosome that protects them.

Dr Stephen Scherer, director of the centre for applied genomics at SickKids, said: "While these women are protected, autism could appear in future generations of boys in their families."

According to the researchers – who formed these conclusions following a study of 2,000 individuals, this could help to explain why autism affects one in 70 boys, compared to a rate of one in 120 among all children.

It could also open the door for the potential development of new treatment options.

According to figures from the National Autistic Society, there are more than 500,000 people with autism living in the UK.