It has long been known that as a woman ages, the odds of
her giving birth to a baby with Down’s syndrome increase.
New research indicates that the children of older fathers
are also at greater risk, though for other brain disorders
including schizophrenia, bipolar disorder and autism.
According to a recent article, “The Father Factor,” by
Paul Raeburn in the February/March issue of Scientific
American Mind, the risk of a man over 40 fathering a child
who eventually develops schizophrenia is the same as the
risk of a mother over 40 giving birth to a child with Down’s
syndrome. One study, the article reports, found if a father
is younger than 25, the chance is 1 in 141 that the child
will develop schizophrenia. At ages 25-29, the
chances are 1 in 121. At 30-34, 1 in 99; at 35-39, 1 in 85;
at 40-44, 1 in 80; at 45-49, 1 in 68; and at 50-55 1 in 47.
So far the results have been replicated in at least seven
other studies. Other studies show a similar factor with
autism, which, the article states occurred at a rate of six
in 10,000 among the children of the younger fathers ranging
up to 52 in 10,000 for fathers over 50. Additional studies
show an increased risk of bipolar disorder in the children
of older fathers.
These increased risks seem to be the result of
age-related degradation of the DNA contributed by the
father. Researchers are working on the genetic mechanisms
hoping to develop better treatments or even a cure for these
devastating brain disorders.
The article concludes, “For now, prospective parents
might want to rethink their plans about when to have
children, says Herbert Meltzer, a psychiatrist and widely
recognized schizophrenia expert at Vanderbilt University. He
believes the risks for children of older fathers will
eventually be seen to be as noteworthy as the risks facing
older mothers. ‘It’s going to be more and more of an issue
to society,’ he notes. ‘Schizophrenia is a terrible disease,
and anything that can be done to reduce it is terribly
important.’”
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