What does delayed fatherhood have to do with autism ...
We hear about the risks of delayed motherhood every other day. But what about the risks that go with delaying fatherhood?
A new finding, published in the Journal Nature, linking old sperm to autism, along with schizophrenia, suggests that maybe a man?s age does matter after all.
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. ?The older we are as fathers, the more likely we will pass on our mutations,? says lead author K?ri Stef?nsson, chief executive of deCODE Genetics in Reykjavik. ?The more mutations we pass on, the more likely that one of them is going to be deleterious.?
These mutations occur each time a man?s sperm cells divide. According to this article, sperm undergoes DNA replication roughly 840 times by the time a man reaches 50 years old.
Dr. Stefansson?s team compared the genetic information of 78 trios of mother, father and child, keeping an eye on spontaneous mutations present in the child that were not present in the parents. They found, don?t ask me how, that the number of mutations passed on by the fathers was nearly four times those of the mothers.
Not only that, but correlations between age and the number of mutations passed to the child were notable:
The father?s age also accounted for nearly all of the variation in the number of new mutations in a child?s genome, with the number of new mutations being passed on rising exponentially with paternal age. A 36-year-old will pass on twice as many mutations to his child as a man of 20, and a 70-year-old eight times as many, Stef?nsson?s team estimates.
While everyone displays inherited mutations in their genetic makeup, the more mutations the higher the chance of having one which is linked to the risk for autism and, possibly, schizophrenia.
A N.Y. Times report on this study, concludes:
In the end, these kinds of mutations may account for 20 to 30 percent of cases of autism, and perhaps schizophrenia, some experts said. Dr. Stefansson and other experts said that an increase in the average age of fathers had most likely led to more cases of autism. Unlike other theories proposed to explain the increase, like vaccinations, it is backed by evidence that scientists agree is solid.
The N.Y. Times also points out that the birthrates for fathers over 40 have increased far more than 30 percent in the past 30 years, yet the rate of autism diagnosis is ten times what it was back then. Therefore, this finding doesn?t begin to explain the increasing rate of autism.
But it does suggest that women aren?t the only ones who need to worry about how time affects reproduction. Having a mature husband, he was 48 when we had our first daughter, I can only deduce that older dads, and moms, make beautiful and brilliant babies.
Should young men be freezing their sperm the way women freeze their eggs?
Image: public domain
Source: http://blogs.babycenter.com/mom_stories/what-does-delayed-fatherhood-have-to-do-with-autism/
julian beever appeasement ian stewart ian stewart odom vt vt