Older fathers are almost twice as likely to have autistic children as younger men, research has found.

Father age link to autism in children
Older fathers are almost twice as likely to have autistic children as younger men, research has found.

By Rebecca Smith, Medical Editor
Last Updated: 12:31AM BST 01 Oct 2008

A small study of children with autism spectrum disorder, the umbrella term for a range of similar conditions, found they were more likely to have been fathered by men over the age of 33.

There was no link with the condition and the mother's age, the Japanese study found.

The research involved 84 children with high-functioning autism spectrum disorders, meaning they had the social impairments of the condition but had normal intelligence, and 208 children without the disorder.

Children whose fathers were over 33 were 1.8 times more likely to have autism than those fathers were under 29. Men who fathered children between the age of 29 and 32 were 30 per cent more likely to have an autistic child.

The research is published in the British Journal of Psychiatry.

This is the first study to explore the effect of paternal age on the risk of high-functioning autistic spectrum disorder. Its findings correspond with previous studies which have shown a link between older fathers and a low IQ in children.

Benet Middleton, director of communications at The National Autistic Society, said: "The causes of autism are still being investigated. Many experts believe that the pattern of behaviour from which autism is diagnosed may not result from a single cause. Autism affects around one in 100 people in the UK and does not solely affect children of older parents.

"Members of the NAS are made up of parents of children from a variety of ages and backgrounds; in addition there is evidence to suggest that complex genetic factors are responsible for some forms of autism."

Some experts have argued that the measles, mumps and rubella vaccination is linked to the development of autism but this has been widely discredited and other studies have failed to find any link.