Nature
may have a reason why some men are infertile,
say researchers who found that the inability to reproduce may be linked to cancer. Scientists
at the University of California at San Francisco discovered that some infertile
men showed a DNA repair problem. DNA, the genetic code that makes humans who
they are, usually has its own repair system to protect the body from developing
disease. But if broken, faulty DNA can lead to health problems. This same DNA
problem associated with infertility in men, researchers report, is also
associated with tumor growth. Cancer is
the result of cells growing uncontrollably because DNA was unable to keep cells
in check. The California research team compared 10 men, five with normally
functioning testes and five whose testes produced little or no sperm. The latter
group showed a 100-fold higher rate in DNA errors than the men with normal
testes, researchers report in the June issue of Human Reproduction, a
British medical journal. The researchers
also point to previous studies involving animals. When genes responsible for DNA
repair were altered in mice, the mice developed tumors and also became
infertile. It's not known whether an
infertile man with this type of faulty DNA who has a child through assisted
reproduction will pass the faulty DNA on to the child, and if the child would be
at risk for developing cancer. "The implications are that maybe infertility is
not a minor problem," says study co-author Dr. Paul Turek, a professor of
urology. "Maybe there is a very good reason for men to be infertile." --ByKatrina Woznicki
