Older Sperm Are More Damaged, U.S. Study Shows
Wed December 17, 2003 07:09 PM ET

WASHINGTON (Reuters) - The older men get, the more damaged their sperm are genetically, U.S. researchers reported on Wednesday.

This could help explain recent findings that show older men are more likely to father children with birth defects, as well as to be less fertile than younger men, the team at the University of Washington in Seattle said.

Narendra Singh and his colleagues tested 66 men aged 20 to 57 and found the older men produced a higher percentage of sperm with highly damaged DNA.

Writing in the journal Fertility and Sterility, they said they could not tell any difference simply by looking at the sperm. The total number of sperm and sperm shape were not affected by age, they said.

But DNA tests showed that older men had more sperm with highly damaged DNA than younger men. And the older men's sperm were less likely to undergo a self-destruct mechanism called apoptosis, which is meant to get rid of damaged cells.

It may not be simply age that affects the sperm, but all the environmental damage that comes with age, the researchers said. While men produce fresh sperm daily, the organs that are involved in sperm production can be affected by smoking, chemicals, sunlight and lifestyle.

"Unfortunately we can't stop age, but men who are putting off fatherhood might want to consider their lifestyle choices to minimize their risk of infertility, or perhaps revise their timetables," said Dr. Anthony Thomas, president of the Society for Male Reproduction and Urology.

"It takes healthy sperm to make a healthy baby and with more research, we can perhaps determine how to best protect sperm from DNA damage."

From: C-upi@clari.net (UPI)
Subject: Older dads risk deformed babies
Organization: Copyright 1997 by United Press International
Date: Wed, 23 Jul 1997 19:30:37 PDT

BAR HARBOR, Maine, July 23 (UPI) -- A leading genetics researcher says men, as well as women, are taking a risk when they wait too long before having children.

Genetic flaws in sperm from aging fathers can cause birth defects, including misshapen skulls and fused hands and feet.

Dr. Ethylin Wang Jabs of the Johns Hopkins University School of Medicine issued her warning today at an annual genetics briefing at the Jackson Laboratory in Bar Harbor, Maine.

Jabs says mutations in sperm of men older than age 35 have been linked to a rare birth defect known as Apert syndrome. But there are signs that mutations in aged sperm may play a role in other syndromes, such as Crouzon and Treacher-Collins, which also cause such features as drooping eyes, misshapen skulls, bulging eyes or foreheads and seriously deformed hands and feet.

In the majority of cases these abnormalities are purely cosmetic, not signs of other problems with health or intellect. The abnormalities can be corrected surgically although sometimes as many as 20 operations may be needed during a lifetime to maintain a normal appearance.

Jabs says scientists think it takes the interaction of hundreds of genes to build a human face, and ``so many of these genes are now coming out.''

One family of genes, called FGFR, appears to be a major player in the development of many conditions in which there are facial deformities. Another gene, called TWIST, causes a similar set of defects.

Jabs says about 2 to 3 percent of all babies are born with a major birth defect and another 2 to 3 percent have a malformation detected during the first five years of life.