Thursday, September 27th, 2012
The scientific paper describing the increases in DNA mutations that correspond to increases in paternal age – published last month (click here to see my discussion of the scientific aspects of the study) – has generated lots of discussion about the need for reconsidering how age may affect paternity and fathering. See, for example, Lisa Belkin’s thoughtful discussion about the utility of men hearing the ticking of a biological clock.
It can be argued that the biological role of fathers, with respect to age, has not received as much attention because we think of the biological clock as primarily representing the probability of being able to reproduce – with those effects being, of course, most pronounced for females. What is now emerging into the public awareness (based on a number of studies conducted over a number of years) is that paternal age – like maternal age – may be associated with an increased risk for passing on certain genetic risk factors that may confer risk for disorders.
We may get to a point where there are risk charts that quantify the increasing probability of paternal mutations that correspond to age and associations with risk for various disorders in offspring (much of the interest right now comes from the potential links between paternal age and autism). Consider, for example, this chart showing the increasing probability of having a child with Down syndrome as predicted by maternal age.
The complexity here is that prospective parents have to consider, in most cases, probabilities rather than certainties (unless there is a screening for a known genetic disorder that runs in a family). Is a 1% chance, versus a .5% or a .01% chance, enough to change someone’s family planning? This is tough to answer. For some people, it may be highly influential. For others, social and personal factors may override such probabilities. What is clear is that genomic research will continue to deliver more and more probabilities in the future (near and far) – and the information that is generated will pertain to both prospective moms and prospective dads. And that prospective parents will have to make more and more complicated choices that are partially (but not fully) informed by genomics.
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