One in a Million: Carrier Genetic Testing

The amount of knowledge in our genetic code is astounding. It tells us everything, from what color of eyes you’ll have to whether you might be predisposed to developing breast cancer. And while a lot of genetic testing is currently done to evaluate personal health risks, couples thinking about becoming parents have the option to screen for various genetic conditions that may affect their future children. Essentially, screening helps to estimate a couple’s chance for having a child with a genetic condition and provides family members with information they may have never known.

“Everyone is most likely a carrier for some genetic condition,” explains Shelby Brown, MS, certified genetic counselor at Sanford Health. “Most carriers identified through carrier screening will not have associated health problems. However, when both parents are carriers for the same condition, the chance for having a child with a genetic condition greatly increases.”

While some people may be aware of conditions that run in the family, carrier testing allows parents to find out about the possibility of those one in a million situations.

“When you are mixing two sets of genes, anything can happen,” says Brown. “In these cases, knowledge can be power. If you discover you are both carriers for cystic fibrosis – a genetic condition that is common in the Caucasian population – screening during pregnancy can be completed and parents can use the information to make delivery plans and even future therapy plans.

Carrier screening will screen for many different hereditary conditions. For some couples, this type of information can seem overwhelming or cause anxiety. So one of the first things a genetic counselor will do when talking about carrier testing is ask what some of these conditions or knowledge of the screen results may mean to the couple. For example, is the couple concerned about a certain genetic condition? Or, if the couple found out they are carriers for the same condition, would their pregnancy management change?

“Carrier testing is a personal choice,” says Brown. “Before we start, we ask what the couple is looking to gain from it. There is such a broad range of information that can come from a genetic test that we want them to know all of the ins and outs of testing.”

The overall process for carrier screening is extremely simple. Couples will give either a blood or saliva sample at the clinic. These samples will then be sent to an outside laboratory to be analyzed and evaluated. Results typically take two to three weeks to get back. But at that time, couples can again meet with a genetic counselor to go over the findings and discuss what genetic conditions the family may be carriers for and what conditions their future children may be at increased risk of developing.

Carrier screening can be completed in multiple stages. A couple can have carrier screening completed at the same time and receive their results together, or one individual can be screened first. If one individual is screened first, the couple can review the results, decide whether or not the information is helpful or concerning, and then further decide if the other partner should have screening completed.

“With these types of tests, there is never a zero percent chance or a 100 percent chance,” explains Brown. “The test may indicate a child could be born with Phenylketonuria (PKU), but it’s not an absolute guarantee. That is why the genetic counselor role is so important. We can really help couples better understand and decide what they wish to do with the information. Overall, screening is a personal decision, but genetic counselors are available to help every step of the way.”

Call (605) 312-GENE to learn more.