Genetic Screening Can Uncover Risky Matches at the Sperm Bank
A startup called GenePeeks will identify recessive diseases that could show up in children of sperm-bank clients and donors.
Genetic analysis can reduce the odds that someone conceived artificially will inherit a dangerous disease.
Within the next year, women choosing a sperm donor may be able to use a genetic-analysis service that identifies those with DNA that could cause disease if combined with their own.
Sperm donors are already screened for a handful of genetic conditions, and recipients can choose between donors based on qualities such as height, athleticism, and education. A more detailed analysis of how donor DNA would combine with the recipient’s DNA would be the next step.
A company called GenePeeks will use DNA-scanning microarrays, which are cheaper to use than whole-genome sequencing, to examine the roughly 250,000 DNA bases in the genomes of sperm-bank clients and donors. The company will then use what’s known about how DNA is mixed and divided during egg and sperm formation to compute thousands of virtual child genomes. Each of these virtual genomes will then be analyzed for disease risks. Donors that produced virtual babies that inherited a genetic disease can then be excluded.
GenePeeks is about six months away from launching its service and will soon announce its initial partner sperm bank, says CEO Anne Morriss.
Today, sperm banks screen potential donors for certain genetic conditions depending on their ethnic background, and all donors are screened for a defective copy of the cystic fibrosis gene. One damaged copy is not enough to affect the offspring (the child would be a carrier of the disease, but would not suffer from it), but if two copies are passed on—one from a donor, one from the mother—then the child will have the chronic and often fatal disease.
GenePeeks will also scan for thousands of other disease risks that are caused by two defective copies of a single gene.
The inspiration for the company came from Morriss’s own experience with sperm donation. Her son, Alec, was born using donor sperm, and he suffers from a genetic condition that prevents his body from converting fats to energy, which can lead to coma, seizures, and sudden death. No one in Morriss’s family had ever had the condition, but she carries one defective copy and, by chance, she picked a donor who was also a carrier.
“The thing I think about every single day is essentially Alec’s disease was preventable,” says Morriss. So she and Princeton geneticist Lee Silver cofounded GenePeeks, which will use Silver’s proprietary algorithms to compute thousands of virtual child genomes. Each of these virtual genomes can then be checked for disease risk. “We want to make sure that we reduce the number of kids that have to pay that price,” says Morriss. “We are at a place as a species that we can do this.”
The idea is not to find the perfect match for a sperm-bank client, but to rule out potentially risky matches. So instead of a list of 300 potential donors to choose from, a woman who uses GenePeeks’s service may be choosing from a pool of 250, says Silver. “We aren’t telling her what to choose, but if she wants to, she can avoid certain donors,” he says.
The excluded donors will differ from client to client. “These donors might be perfectly good for another woman—it is very specific to the combination of genes,” says Silver.
Experts in assistive reproduction say the idea behind GenePeeks is potentially beneficial to families, but they also emphasize the need for good genetic counseling. One concern for Richard Scott, a reproductive endocrinologist, obstetrician, and gynecologist and founding partner of the Reproductive Medicine Associates of New Jersey, is that the risk may never seem low enough to some sperm-bank clients. “What you don’t want is for this to be so scary that people aren’t going to have a family,” says Scott. To understand the risk properly, “they need to have a really substantial counseling piece that is high quality and uniformly applied,” he says.
Joe Leigh Simpson, senior vice president of research for March of Dimes, a nonprofit focused on reproductive health, and an obstetrician and gynecologist who specializes in genetic medicine, agrees that counseling is critical, especially given the scientific community’s growing but nascent understanding of the genetic basis of disease (see “By Simply Sharing, Doctors Could Unlock the Genome’s Potential”). “Couples need to be aware that they could leave this frustrated, because medical science is not in a position to tell them what all of their changes mean right now,” says Simpson.
Morriss says that GenePeeks is in the process of building a genetic counseling team that will work with both clients and donors, but in the end, the only results that clients will see is a customized list of sperm donors. Client and donor DNA itself will not be analyzed for disease risk. Only the virtual child genomes will get the disease-risk interpretation. In cases where the analysis uncovers a high risk for transmitting a genetic disease, the genetic counseling team will either tell the client or donor directly, tell his or her physician, or say nothing at all, depending on the client’s or donor’s instructions prior to testing.
The company is still figuring out exactly how to handle some important issues such as whether or not the company will tell participants they are carriers of genetic disease. GenePeeks will provide raw genome scan data to donors or clients who request it and will encourage them to have it interpreted by a genetic-analysis service, says Morriss.
She says the service will likely cost less than $1,000. “We want to make it accessible,” says Morriss. “That’s why we are working with [microarray] technology.” She says the company can use more thorough sequencing-based technologies when the price is right.
Couldn't get to Cambridge? We brought EmTech MIT to you!Watch session videos here