Should Donated Sperm Be Screened for Genetic Mutations?
The October 21 issue of the the Journal of the American Medical Association brings to attention how an undetected genetic mutation in one sperm donor can affect his offspring. It also triggers questions of appropriate screening of sperm donors as technology has improved the ability to screen for genetic mutations.
The case study done by Barry J. Maron, MD, of Abbott Northwestern Hospital in Minneapolis, and colleagues reports on a man who donated sperm at age 23. At the time he was in good health, and asymptomatic, with no history of cardiac disease. He donated his sperm on multiple occasions over a 2-year period in 1990-1991. Screening included a comprehensive personal and family history, physical examination, and laboratory testing for infectious and transmittable diseases (HIV, syphilis, hepatitis B and C, cytomegalovirus,gonorrhea, chlamydia, and Tay-Sachs disease).
When one of his offspring was diagnosed with hypertrophic cardiomyopathy in 2005, the system was triggered notification to all known recipients of this donor's sperm that an inherited form of heart disease could have been transmitted to their children. Genetic testing was offered first to the donor and later to the offspring.
The mutation (Arg169Gly), associated with hypertrophic cardiomyopathy, was found to be present in nine of his 24 offspring. Two of the children he fathered with his wife. One of the donor's children died from heart failure resulting from the disease at age 2.
Three of the offspring have phenotypic evidence of the disease, including the one who died at age 2 from progressive and unrelenting heart failure with marked hypertrophy. The two survivors are 15 years old and have extreme left ventricular hypertrophy. Both of them, along with their biological father, are believed to be at increased risk for sudden death.
The seven other survivors with the mutation are asymptomatic, the researchers said.
In hypertrophic cardiomyopathy, the heart muscle thickens abnormally, to the point where it makes it difficult for blood to leave the heart, forcing the heart to work harder to pump blood through the body.
How much screening of donated sperm should be done for genetic diseases? This study’s researchers say their findings call for improved genetic screening guidelines for gamete donors and a national database of donor information.
The FDA inspects operations at sperm banks, but focuses on preventing the spread of infectious disease. The American Society for Reproductive Medicine recommends genetic screening for gamete donors, however compliance is voluntary.
Donation banks rely heavily on family history. Some common genetic conditions are tested for, including cystic fibrosis and sickle cell traits.
* Maron BJ, et al "Implications of hypertrophic cardiomyopathy transmitted by sperm donation" JAMA 2009; 302(15): 1681-84.
* Daar JF, Brzyski RG "Genetic screening of sperm and oocyte donors" JAMA 2009; 302(15): 1702-04.