While the link between older fathers and autistic children is likely to be genetic, the researchers who conducted the new study also acknowledged the possibility that unknown other factors could simultaneously be causing men to delay parenthood while independently increasing autism rates.It seems to me that, paradoxically, this is backwards. If paternal age itself somehow leads to autism, then the cause is less likely to be genetic (a father's genes don't change as he ages, but epigenetic factors could play a role). On the other hand, if there are factors that simultaneously delay parenthood and induce autism, those factors could be genetic. Under this hypothesis, fathers with certain alleles are more likely to be fathers late in life, and those same alleles, inherited by the child, could cause a predisposition towards autism.
Tuesday, September 05, 2006
The Washington Post describes a new study by Abraham Reichenberg and colleagues showing a significant effect of paternal age on autism rates (link). The author, Shankar Vedantam, ends with this: