Posted on December 22, 2009

Mapping the God of Sperm

Rachel Lehmann-Haupt, Newsweek, December 16, 2009

{snip} Maxey [Kirk Maxey], 51, happens to be one of the most prolific sperm donors in the country. Between 1980 and 1994, he donated at a Michigan clinic twice a week. He’s looked at the records of his donations, multiplied by the number of individual vials each donation produced, and estimated the success of each vial resulting in a pregnancy. By his own calculations, he concluded that he is the biological father of nearly 400 children, spread across the state and possibly the country.

When Maxey was a medical student at the University of Michigan, his first wife, a nurse at a fertility clinic, persuaded him to start donating sperm to infertile couples. Maxey became the go-to stud for the clinic because his sperm had a high success rate of making women pregnant, which brought in good money for the clinic. Maxey himself made about $20 a donation, but says he was motivated to donate more out of a strong paternal instinct and sense of altruism. “I loved having kids, and to have these women doomed to wandering around with no family didn’t seem right, and it’s easy to come up with a semen donation,” he says. {snip}


“I had this ‘Oh my God’ moment, thinking, how many kids have been produced?” he says. “I thought the doctors were keeping track of each birth, but when I realized they weren’t, I began to worry. What if they start dating one another?” He also began to worry about their genetic health. “I wanted to know if I have anything totally lethal or deranged or recessive in my genes that I may have passed along.”

These were questions that neither the sperm bank nor the government was asking. Several times Maxey tried to contact IVF Michigan, the bank where he made most of his donations, but it refused to release any information, noting that he signed a waiver to give up his rights to know who used his sperm. That’s still common practice among sperm banks unless a donor has agreed to be an “identity release” donor, which gives his offspring the right to get in touch when they turn 18. Even today, sperm banking is not strictly regulated. Currently, there are only recommended guidelines put in place by the American Society for Reproductive Medicine that say a donor should be required to provide a complete medical history to rule out “genetic abnormalities” or a family history of inherited disease and should receive proper counseling. The FDA has guidelines saying that a clinic cannot use a donor with a “relevant communicable disease agent or disease,” but does not require genetic testing. Most banks do not do genetic testing either. Despite these loose attempts at guidelines, sperm banking continues to raise a host of ethical, medical, and financial questions. There’s no social template for donors who are found by their offspring, or even rules about how many children should come from a single donor.

Clinics are now struggling to answer some of these questions. In October, The Journal of the American Medical Association reported that a 23-year-old donor used by a San Francisco sperm bank passed on a potentially deadly genetic heart condition to nine of his 24 offspring, including one who died of heart failure at the age of 2. The sperm bank now gives electrocardiograms to screen for genetic heart diseases among potential donors.

Dr. Cappy Rothman, the medical director of the California Cryobank, says that his bank does extensive genetic screening. “We have a medical advisory board that constantly reviews our testing and adds any additional tests we feel will help protect our clients and their future children,” he says.


With just a blood and skin sample, scientists at the PGP project were able to isolate strands of Maxey’s DNA. These strands of DNA make proteins that drive the chemical reactions that make our bodies and brains run, and regulate the expression of our genes. Within these strands, there are unique sequences of A, C, T, and G molecules–the language of DNA–called nucleotides. Variations in these sequences called single nucleotide polymorphisms, or SNPs (pronounced “snips”), make individuals differ, and they serve as signposts for variants of a nearby gene on the DNA highway. Maxey worried that one of his SNPs would turn out to be a recessive mutation expressed as a disease such as Tay-Sachs or cystic fibrosis that would be passed along to his children.

Fortunately, Maxey’s genome has turned up nothing shocking so far: he has a 1.9 percent increased risk for coronary heart disease compared with the general population. He has a reduced risk for Alzheimer’s and a reduced risk of baldness, which surprised him considering he has lost most of his hair. “The question is not whether everything is predictable from genes alone–or even genes plus environment, but whether we can improve quality of life with deeper knowledge of genes and environment,” says Church. “The PGP hopefully will turn up lots of examples of people sharing [DNA sequences] but having divergent medical outcomes because of differing lifestyles, medications, and diets.”

But where Maxey’s public genome can get really interesting is the way that his children may be able to figure out if indeed he is their biological father without ever seeing him face to face. This is possible through something in the genetic code called short tandem repeats. These are sequences of A, C, T, and G molecules that repeat themselves over and over along an individual strand of DNA and are specific to that individual’s DNA.

Potential offspring could have some of their genetic markers run for a couple of hundred dollars by a company such as Family Tree DNA or, and then take those markers and look at Maxey’s genome markers, which are now not only posted on the Personal Genome Project, but also on the Donor Sibling Registry. “If they see the same short tandem repeat number, then it’s very probable that I’m their dad because they would inherit the same pattern from me,” Maxey explains.


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