Home DNA testing kits have become increasingly popular in recent years and there are now many different companies, like 23andMe, Ancestry, and National Geographic, that offer this service to consumers commercially. Without ever leaving their home, people can order a genetic testing kit, take a DNA sample, and send it back for testing. The results offer detailed data about ancestry, migration, and personal physical or character traits. Some of these companies are even offering health testing that includes carrier status information for some diseases. But how does this compare to other, more established forms of genetic carrier screening?
Genetic Carrier Screening
All methods of genetic carrier testing can give you an idea of how likely you are to pass a certain genetic trait or condition on to your offspring. There are hundreds of possible variants or genetic diseases that can be tested for in any individual. The likelihood of your child developing a genetic condition depends on a variety of factors, such as how it is inherited (what chromosome the genetic mutation is associated with) and what genetic variants your partner has. Carrier genetic testing can be performed with a saliva sample, a buccal swab, or a blood test.
Most commercially available at-home testing kits are only intended for autosomal recessive carrier screening. When a baby is conceived, they inherit a gene from each parent for every trait. An autosomal recessive disorder occurs when a person inherits two genes that cause the disorder, one from each parent. A person can also be a carrier, which means that they only inherited one of these genes, and therefore do not have the disorder but are at risk of passing it on to their offspring. If one partner tests positive as a carrier for a particular genetic disorder, the other partner will also need to be tested to determine if their child has a risk for being born with the autosomal recessive condition.
In reality, there are many different kinds of inherited disorders. Genetic diseases that are inherited in other ways (like X-linked inheritance, when there is a mutation on the X chromosome) usually can only be tested for with more thorough forms of carrier genetic testing, performed through a blood test at a healthcare provider’s office.
If you are interested in a comprehensive list of genetic conditions that you should consider getting screened for, your best bet is speaking to your doctor about the different carrier screening tests. The tests recommended by your doctor can often provide more information and information about additional genetic diseases not found in today’s at-home DNA testing kits. Before you decide what kind of genetic test is good for you, you should have a good idea of what genetic diseases or variants should be tested for and make sure your selected test meets these criteria.
At-home DNA tests are done precisely that way, in your own home and under your own supervision. It is obvious that their accuracy may be affected by many environmental factors such as human error during sample collection. A huge benefit of getting a blood test for carrier screening is that your sample is taken by a professional and is handled by laboratory-trained technicians throughout the process. These laboratories have many years of specialized experience dealing specifically with DNA carrier screening. This can lead to higher quality samples and therefore, higher quality results.
Consult Your Doctor
It can be fun to find out about your ancestry and where your family came from, but when you are also testing for risk or carrier status for certain health conditions, it is best to consult with an expert. If you have questions about which kind of genetic carrier screening to perform, you should consult your doctor for more information. When you receive your results, you will likely bring them to your health professional or genetic counselor for guidance on next steps, so it makes sense to consult them beforehand about which kind of testing they prefer.
If you move forward with the at-home carrier screening kit, it’s important to note that depending on your results, additional testing may be recommended. Your doctor may order additional tests, like a carrier DNA screening or panel (performed via blood draw) to confirm your at-home results.