Previous posts have discussed evidence concerning a possible link between autism and paternal age. The New York Times reports:
Older men are more likely than young ones to father a child who develops autism or schizophrenia, because of random mutations that become more numerous with advancing paternal age, scientists reported on Wednesday, in the first study to quantify the effect as it builds each year. The age of mothers had no bearing on the risk for these disorders, the study found.
Experts said that the finding was hardly reason to forgo fatherhood later in life, though it may have some influence on reproductive decisions. The overall risk to a man in his 40s or older is in the range of 2 percent, at most, and there are other contributing biological factors that are entirely unknown.
But the study, published online in the journal Nature, provides support for the argument that the surging rate of autism diagnoses over recent decades is attributable in part to the increasing average age of fathers, which could account for as many as 30 percent of cases.