Beijing, Oct 21 : An American sperm donor, who has an undetected genetic mutation linked to a heart disease, passed on a potentially deadly condition to nine of his
24 offspring, one of whom died from heart failure at age 2, said a case report in Wednesday's Journal of the American Medical Association.

According to Barry J. Maron, MD, of Abbott Northwestern Hospital in Minneapolis, the mutation, associated with hypertrophic cardiomyopathy, was discovered only after one of the donor's biological children tested positive for it.

Hypertrophic cardiomyopathy thickens the heart and makes it harder to pump blood. It affects about one in 500 people; many more likely have the genetic defect without symptoms, said study co-author Heidi Rehm of Harvard Medical School. The symptoms can include an irregular heartbeat and shortness of breath but many cases go undetected until sudden death, Xinhuanet reported.

The children are now aged seven to 16. Nine, including one born to the donor's own wife, have been tested positive for the heart mutation. One born through sperm donation died; two others have developed symptoms, with one getting a defibrillator. The remaining children are at increased risk for problems, which often do not show up until adolescence, Maron said.

For privacy concerns, neither the sperm bank nor the donor was identified. The donor, now 42, had no symptoms of genetic heart disease and no obvious family history when he donated sperm in the early 1990s. His own condition was not diagnosed until after a child born through sperm donation was diagnosed.

The researchers said the case calls for improved genetic screening guidelines for gamete donors and a national database of donor information.

"This case series underscores the potential risk for transmission of inherited cardiovascular diseases through voluntary sperm donation, a problem largely unappreciated by the medical community and agencies regulating tissue donation," they said.

The San Francisco sperm bank now gives all donors electrocardiogram tests to weed out men with genetic heart problems and the researchers recommend that other sperm banks follow suit (IANS)