Why Men Should Give a Spit About Genetic Carrier Screening

You may have your mother’s eyes or her freckles. Or maybe your father’s hair or his dimples. What our parents pass down to us is a source of fascination, but it’s also science.

Every child gets the same amount of genes from the mother and father. It’s a 50/50 split. So why is it that when couples are planning to have a child, more women than men are the ones having genetic carrier screening? Men, let’s step up to the plate.

Every child gets the same amount of genes from the mother and father. It’s a 50/50 split. So why is it that when couples are planning to have a child, more women than men are the ones having genetic carrier screening? Men, let’s step up to the plate.

Carrier screening is genetic testing that determines if you carry a variant (change) in a gene that may have implications for your children. Being a carrier usually doesn’t affect your own health — typically carriers don’t even know they are carriers. But if both you and your partner are carriers for the same condition, there’s a 25% chance that of having a child with that condition, and a 75% chance of having an unaffected child. Those are independent probabilities for each pregnancy, so there’s a 25% chance each time and a 75% chance each time.

You can see why it’s important for men to get tested — they put in just as much genetic makeup as a woman. Just because the woman is the one carrying the baby doesn’t mean she should be the only one having carrier screening.

Estie Rose, a certified genetic counselor at JScreen, a nonprofit genetic testing program based at Emory University, explains that in the earlier days of carrier screening, testing was usually done only for the female partner for a limited number of conditions based on her ethnic background. For example, if she had an Ashkenazi background, she would be screened for the Ashkenazi panel, which included diseases more common in this group like Tay Sachs. Then, only if she tested positive was the male partner tested.

The advent of saliva testing makes carrier screening much easier to administer through home testing.

Because testing at the time was much more expensive, this testing model made sense. But now that technology has progressed and become a lot more accessible and affordable, partners can be tested at the same time. Also, the advent of saliva testing makes carrier screening much easier to administer through home testing. Carrier screening done via saliva is just as accurate as via blood.

The breadth of the diseases that are screened have also increased, allowing individuals to have a more comprehensive understanding of their carrier status. Instead of being tested just for diseases that are most common in their ethnic background, a wider net is cast to include a larger number of diseases that are common across ancestry groups.

Daniella Kamara, a licensed genetic counselor at UCLA David Geffen school of Medicine and a consultant for GeneTestNow, an awareness and education nonprofit the Jewish Journal helped launch and market, explains this approach. “We’ve gone from the idea of testing individuals based on their ancestry to conducting pan-ethnic panels on everybody. The technology today is built in a way that looking at one gene and looking at 200 genes is the same. So generally speaking in today’s genetics world, anybody that comes through the door for carrier screening gets a pan-ethnic panel that looks at usually over 200 genetic conditions that are common in all different ancestries and exist in the population. For example, we know that although Tay Sachs, yes, is more common in Ashkenazi Jews, there are plenty of people who are not Ashkenazi Jews who are also Tay Sachs carriers. And the same goes for other diseases as well.”

This approach also addresses the growing mix of the population, not just with interfaith couples but marriage within the Jewish community between individuals of Sephardic, Mizrahi, Persian and Ashkenazi descent. 

What if you’ve already had done a genetic test with a company like 23andMe? Does that mean you don’t need any additional carrier screening? Rose argues that these direct-to-consumer tests are fine for purposes like learning what your ancestry consists of, or if you have genetic traits like cilantro tasting like soap. But these tests should not be used to make medical decisions.

Even though these services might include carrier information as part of the test package, the number of diseases on their panel is limited. Also, a report is presented without the benefit of a genetic counselor helping you to navigate the results. What does it mean to be a carrier if you are one? What does a positive result mean? What are your options? With these ancestry tests, you’re on your own. “Any medical-grade genetic test should be performed by a certified lab and genetic counseling should be included. Genetic counselors are trained to interpret genetic results and to convey them in a way that is understandable to the lay person,” adds Rose.

So if you’re thinking of being a father or know someone who is, remember it takes two to tango. And both tango partners need carrier screening. Happy Father’s Day.

For more information on genetic carrier screening, visit genetestnow.com.