Older dad’s offspring are much more likely to develop schizophrenia. The flip side is that having kids before you’re 25–as opposed to age 50–can cut your risks in half.
Due to more mutations in sperm, the odds of developing diagnosable schizophrenia rise 30 percent with each ten-year climb in paternal age. And now comes news from Columbia University to suggest links between aging fathers and actual gene expression of both schizophrenia and autism in next generations.
The research gazes beyond the genome to the epigenome to look not simply at changes in the genes themselves but in how they are expressed.
Such epigenetic changes in sperm, related to aging, have been linked in old mice to a loss of DNA methylation at the locations where the genetic code starts being transcribed, Dr. Maria Milekic told the American College of Neuropsychopharmacology annual meeting in Hollywood, Florida, yesterday.
All things considered, early fatherhood may be the best hedge you can get.
My own guess is that my Irish bloodstream is clogged with older dads. This, I believe, is what helped spike rates of insanity in our family, to say nothing of the wider Irish family. This, I suspect, is why it now pools in our family, taking two of four sisters.
Late age of paternity was one very sturdy leg of my three-legged stool theory of an epidemic of madness that swept over famine ravaged Ireland, surviving in my immediate family today. Of the three legs—alcoholism, older fathers, and starvation—the old geezer phenomenon was the most startling one to find in my quixotic quest back to the grass green land of my insane ancestors.
Everyone knows about the famine leg, the maternal malnourishment that also doubles rates–no hiding that fact of history–but advanced age of fatherhood flies under the radar. In our patriarchal culture, it’s not a hot topic.
Nor is mental illness in general, to be fair. To say that no one in Ireland wants to talk about mental illness is to exaggerate very little. Then again, to be fair to the Irish, no one anywhere seems to want to talk about severe mental illness.
The woes of the worried well are one thing. We talk all day about that. Schizophrenia is weird and spooky and beyond our culture’s conversational comfort zone. The silence says it all.
To utter the word “schizophrenia” on the back lanes of Ireland is to toss a cat among the pigeons–people scatter. You’ll clear the room. No one pretends not to know what you’re talking about. It’s just that, suddenly, everyone has to be somewhere else.
Now try hiking down a few back lanes of old country Ireland while introducing the word “sperm” to the hard-to-have conversation. Been there, done that, got the T-shirt. Can you say fuggedabout it?
The roots of the old Irish father story sink much deeper than you might think. To be frank, it was not exactly wholesome for old Paddies to be taking Irish child brides, but that’s the unfortunate truth of it.
So poor were the Irish, they had to wait for their fathers to pass away before they could inherit the lease rights to the pathetic potato patch that spelled the difference between life and death under the British ruling directly from Dublin Castle.
When they became eligible, they had their pick of parish girls. Men being men . . .
That’s pretty much it. In old Ireland, men tended to marry very late—and women were married off at a very young age.
Or to get rid of them all, to get their hungry mouths off the patch, women were sent to the convent, the youngest brothers to the priesthood, while the oldest son, under this system of primogeniture, was left the patch on which he went forth and multiplied madness.
It wasn’t the fault of the Irish, so they have nothing to be ashamed of. Late age of paternity was absolutely an inseparable part and parcel of the famine economy imposed from the outside.
Along with in-vitro starvation and heavy consumption of white Irish moonshine to medicate the pain, late age of paternity was in the same frame that begins to explain soaring rates of insanity in that cruelest of centuries for our woebegone ancestors.
Epigenetically, I believe, that might even survive to this day, very concretely, in ouru two dear sisters with their lost minds. That’s the gist of my book (once again, available in Kindle or PDF digital form for free at firstname.lastname@example.org).
Many a bachelor was north of 50 before he could get hitched. A Paddy marrying into a family with three or four daughters was suitable at any age. He could be 60 marrying a 16 year-old if they could all partake of his potato patch bounty.
While pockets of intermarriage were known to exist, there’s no evidence to suggest any general prevalence of inbreeding in Ireland. Overall, the Irish gene pool is actually quite rich, but cousins were married in the most desperate pockets of peasant Ireland just to keep the spuds in the family.
Kissing cousins were found “in certain secluded valleys in the west and south of Ireland where intermarriage is common,” according to a report from the time.
Consanguinity is the polite way of phrasing it, and it was a fact of life in some parishes of peasant Ireland. ”Go west for a horse, go east for a woman,” was the admonition of those who sought to “marry out of it.”
So it was late age of paternity–not the more salacious inbreeding story that the uninformed favor–that was the big driver along with in-vitro malnourishment and, of course, alcohol consumption. Here, again, it was the men. Women were not the drinkers in 19th century Ireland.
“We were interested in understanding the mechanism of the paternal age effect,” Milekic said, shining her searchlight on DNA methylation, a biochemical process that plays an important regulatory role in the epigenetics of mental illness.
“The risk for schizophrenia increases 2-fold when a father is over 45 years of age, and the risk for autism increases 2-5-fold. It seemed unlikely that mutation alone could account for this. We therefore speculated that DNA methylation could provide an alternative mechanism.”
Milekic said the next logical step would be to compare brain regions. Most of the genes that have altered expression are in the cerebellum, she said. “We are interested in how DNA methylation in the cerebellum is affected by paternal age.”
As for me, I’m interested in remaining childless. I love kids. Way back in my teens I was wishful of having a bunch of kids one day. That all changed when the schizophrenia torched my sisters.
It’s so hereditary that I’m keeping in mind that one leg of the stool. The older I get, and the more I learn about older fathers, the more determined I am to sit this round out.
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Last reviewed: 11 Dec 2013