"New Point Mutations in Humans Are Introduced Through The Male Line" This Has Been Known Since the 1950s", "What is Intriguing is why society chooses

TO IGNORE THIS" said Malaspina.


But now it is becoming increasingly clear that the biological clock ticks
for men as well as women, as researchers turn up evidence that as would-be
fathers get older, they have an increased chance of passing on genetic
defects to their children.

"New point mutations in humans are introduced through the male line," says
Dolores Malaspina, MD, professor of clinical psychiatry at Columbia
University and the New York State Psychiatric Institute. Furthermore, she
adds, the number of mutations in sperm increases as men age.

"This has been known since the 50s," said Malaspina. "What is intriguing is
why society chooses to ignore this."




CULTURAL RESISTANCE
There are many reason why paternal contribution to birth defects has a low
profile. James F. Crow, PhD, emeritus professor of genetics and medical
genetics at the University of Wisconsin in Madison, mentions that most of
these defects occur at low levels, on the order of 1 in tens of thousands.
In contrast, the odds of having a child with Down syndrome are about 1 in
350 when the mother is age 35 years and 1 in 100 at age 40 years. However,
some scientists hint that society may not be ready to hear that older men,
like older women, run the risk of passing on birth defects.

But the risk of having a child who later develops schizophrenia, Malaspina
notes, is about 1 in 110 when the father is age 40-similar to a 40-year-old
woman's risk of having a child with Down syndrome.

Malaspina says she believes her findings met resistance because of a
reluctance by men to accept that fathering children later in life poses
increased health risks to their children.

"Despite the fact that our paper received excellent reviews it was rejected
by two medical journals," she said, noting that the study results now have
been replicated five times with similar results. "And these biases really
hold us back from scientific advances."






from an article by Paul D. Thacker:

Biological Clock Ticks for Men, Too
Genetic Defects Linked to Sperm of Older Fathers
Paul D. Thacker

JAMA. 2004;291:1683-1685.



[mnchp-l] Genetic Defects Linked to Sperm of Older Fathers
McGillivray, Katrina katrina at beststart.org
Wed Apr 14 10:00:40 EDT 2004