Older parents, epigenomics and psychiatric illness
Posted by Dave Bath on 2008-11-11
Nature’s British Journal of Pharmacology has (for free!) an editorial that is getting my nose twitching, and pushes me to speed up a Balneus post that has been brewing for a while. The growing literature on the diseases of children caused by advanced parental age suggests that the societal pattern of people building their careers before having children needs to be reviewed by social policy makers.
"Epigenetic biomarkers in psychiatric disorders" British Journal of Pharmacology (2008) 155, 795–796; doi:10.1038/bjp.2008.254; published online 23 June 2008 (also as PDF) is yet another paper stressing the importance of epigenetics in pathogenesis, and introduces a new word, "epigenomics" that relates to testing and markers.
Basically, the older the person (male or female) when conceiving a child, the more likely something epigenetic has gone awry and will cause problems.
Another relatively recent paper highlighted the relationship between advanced parental age and schizophrenia: "Aberrant Epigenetic Regulation Could Explain the Relationship of Paternal Age to Schizophrenia" Schizophrenia Bulletin doi:10.1093/schbul/sbm093 (advance publication 2007-08-21) contains the following:
In 2001, Malaspina et al showed that the incidence of schizophrenia increased progressively with increasing paternal age, the risk being 2-fold and 3-fold for offspring of fathers aged 45–49 and 50 or more years, compared with those of fathers aged less than 25 years.
It’s not just schizophrenia: autism, cognitive and learning difficulties, longevity … the list gets longer every year.
It’s a far cry from what we were taught at uni in the seventies: that old ova stuck in meiosis for 40 years accumulated damage (leading to increased incidence of trisomy 21 or Down’s Syndrome), but because spermatogenesis was continuous, older males didn’t cause such problems.
This raises questions about how social policy affects societal health perhaps more serious than the "diabesity" epidemic, as obesity is more easily treated than something caused at the time of conception (even before).
The easy recommendations are
- for ladies: ignore the flattery and bank balances of older men;
- for males: it’s worthwhile trying to settle down earlier, do the parenting bit with your career on hold; and
- for politicians: education patterns and work/life balance policies need some attention – unless we want each generation of teenagers to be nuttier than than the previous one.
Someone in Canberra should be crunching the numbers between the census details on parental age and epidemiology, taking into account greater diagnostic capabilities across the years.
I’m much relieved that at 48, my grandson is approaching 2, not only because of this research, but because I’ve got just enough energy to keep up with him for a couple of days (I stay with my daughter and grandson every second weekend on average). I’d be much less fun for him if my joints were any creakier!