Thursday, January 29, 2009

The Father Factor: Advanced Paternal Age

We are used to the idea that advanced age of mothers places children at risk for Downs' Syndrome. New evidence is coming to light that the advanced age of fathers may be a factor as well. This article from Scientific American is based on the Israeli study I have already reported on this blog, here, here, here and here.
But the article has some new info as well:
Researchers had analyzed medical records in Israel, where all young men and most women must report to the draft board for mandatory medical, intelligence and psychiatric screening. They found that children born to fathers 40 or older had nearly a sixfold increase in the risk of autism as compared with kids whose fathers were younger than 30. Children of fathers older than 50—that includes me—had a ninefold risk of autism.

The researchers said that advanced paternal age, as they call it, has also been linked to an increased risk of birth defects, cleft lip and palate, water on the brain, dwarfism, miscarriage and “decreased intellectual capacity.”

What was most frightening to me, as someone with mental illness in the family, is that older fatherhood was also associated with an increased risk of schizophrenia. The risk rises for fathers with each passing year. The child of a 40-year-old father has a 2 percent chance of having schizophrenia—double the risk of a child whose father is younger than 30. A 40-year-old man’s risk of having a child with schizophrenia is the same as a 40-year-old woman’s risk of having a child with Down syndrome....
a 1912 study not(ed) that a form of dwarfism called achondroplasia was more common among the last-born children in families than among the first-born. Weinberg didn’t know why that was so, but he speculated that it might be related to the age of the parents, who were obviously older when their last children were born. Weinberg’s prescient observation was confirmed decades later when research showed that he was half right: the risk of dwarfism rose with the father’s age but not the mother’s.

Since then, about 20 inherited ailments have been linked to paternal age, including progeria, the disorder of rapid aging, and Marfan syndrome, a disorder marked by very long arms, legs, fingers and toes, as well as life-threatening heart defects. More recent studies have linked fathers’ age to prostate and other cancers in their children. And in September 2008 researchers linked older fathers to an increased risk of bipolar disorder in their children.

Read it all here.

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