Dad's age increases autism risk
 
 September 08, 2006

Guys, hear that ticking?

It’s not your girlfriend’s biological clock. It’s yours.

While increasing maternal age has long been associated with fertility problems and increased risk of Down syndrome and birth defects, new research shows that older dads run a higher risk of having kids with autism.

According to a study in the September issue of the Archives of General Psychiatry, men older than 40 are almost six times more likely than men under 30 to father a child with autism, regardless of how old the mother is. Autism is a developmental disorder characterized by social and language abnormalities as well as repetitive patterns of behaviour. It affects an estimated five out of every 10,000 people and is more likely to occur in boys than in girls.

In the study, a team of Israeli researchers looked at data recorded for more than 132,000 children born in a six-year period and compared data on parental age and autism incidence. Of the children included in the study, 110 had been diagnosed by age 17 with autism or “autism spectrum disorder,�?which includes Asperger syndrome and Rett syndrome. After analyzing the data, the researchers found that men older than 40 were 5.75 times more likely to father a child with autism than younger dads.

This isn’t the first study that should get men’s clocks ticking. Earlier research has linked paternal age to an increased risk of miscarriage as well as of Down syndrome and schizophrenia.

While the reason for the autism-age link isn’t clear, the researchers speculate that as men age, their DNA may loses some ability to repair itself, so spontaneous mutations in sperm-carrying cells may be passed on rather than corrected, or that “silencing�?devices, which control how a gene is expressed, may lose their effectiveness.

“Although further work is necessary to confirm this interpretation,�?write the researchers, “we believe that our study provides the first convincing evidence that paternal age is a risk factor for autism spectrum disorder.�?/FONT>