September 27, 2022

Autism linked to older fathers

Two contemporary trends have been linked by a recent article in Nature: the rising age of first-time fathers and the increasing rate of autism.

Two contemporary trends have been linked by a recent article in Nature: the rising age of first-time fathers and the increasing rate of autism. The study, based on genetic date from 85,000 Icelanders gathered by DeCode Genetics, a company which crunches genetic data, shows that humans inherit more than three times as many mutations from their fathers as from their mothers, and mutation rates increase with the father’s age but not with the mother’s.

This suggests, says Nature, that “By starting families in their thirties, forties and beyond, men could be increasing the chances that their children will develop autism, schizophrenia and other diseases often linked to new mutations.” Although other factors are sure to be at work, this could help to explain a 78% rise in autism spectrum disorder since 2007 in the US.

A scientist who commented in Nature on the article, Alexey Kondrashov, of the University of Michigan, told the New Yorker that “This is really scary.” He believes that older fathers could eventually lead to a “decline in the mean fitness of the population.” “Diagnoses of autism and schizophrenia is one thing, but [older fathers may have] a perfectly normal [child] in the sense that there may not be a diagnosis, but his IQ is 108 instead of 110,” Kondrashov said. “This means this is a problem that will lead to very severe consequences for society over several generations.”

How can this be countered? The logical way – encouraging men to marry earlier — seems a bit too simple for Dr Kondrashov. He suggests that young men freeze their sperm in adolescence. If commitment-phobia and late marriage are characteristics of the sexual revolution, is autism one of its unintended consequences?  

Michael Cook
Creative commons
autism
delayed marriage