Women who continue—or begin—childbearing in their late thirties and beyond are accustomed to hearing about increased risk for certain conditions and complications, both maternal and foetal, on account of advanced parental age. (Some of us have even been subjected to lectures smack in the middle of labour, but that’s a grievance for another day…)
This NY Times Health story, however, puts the shoe on the other foot, or gender as the case may be. Last week, scientists reported that “older men are more likely than young ones to father a child who develops autism or schizophrenia, because of random mutations that become more numerous with advancing paternal age.”
The study’s authors believe the results are unlikely to dissuade older (40 is “older”?) men from fathering children, since the “overall risk to a man in his 40s or older is in the range of 2 percent, at most, and there are other contributing biological factors that are entirely unknown.”
But the study, published online in the journal Nature, provides support for the argument that the surging rate of autism diagnoses over recent decades is attributable in part to the increasing average age of fathers, which could account for as many as 20 to 30 percent of cases.
The findings also seem to provide a balance to the widely accepted and long held belief that maternal age is the most crucial factor in determining the odds of a child having developmental problems. It is known, for example, that the risk of Down syndrome increases for older mothers, but the study found that “when it comes to some complex developmental and psychiatric problems, the lion’s share of the genetic risk originates in the sperm, not the egg.”
As with any such information, forewarned is forearmed, and it may impact couples’ decisions.
If these study findings hold up and extend to other brain disorders, wrote Alexey S. Kondrashov of the University of Michigan, in an editorial accompanying the study, “then collecting the sperm of young adult men and cold-storing it for later use could be a wise individual decision.”
That’s if you can get past the ick factor. I can just see dating site questionnaires in forthcoming decades: “Have you, or are you planning to store the sperm of your youth for future use?” And I’m not convinced that utilizing this sort of technology wouldn’t have unforeseen medical or societal complications of its own—to say nothing of the expense.
On the other hand, the Times article extrapolates:
“You are going to have guys who look at this and say, ‘Oh no, you mean I have to have all my kids when I’m 20 and stupid?’” said Evan E. Eichler, a professor of genome sciences at the University of Washington in Seattle. “Well, of course not. You have to understand that the vast majority of these mutations have no consequences, and that there are tons of guys in their 50s who have healthy children.”
Well said. Could I add yet another piece of advice? Guys, do not listen to the brain researchers who don’t expect you to grow up until you are 26 — or older. You don’t have to marry at 20 but you don’t have to be stupid, either.