Genetics is the study of genes, the DNA that differentiates humans from other species as well as the individual differences we see in each other, and how they are passed from generation to generation. Genes are the reason for our obvious physical traits in addition to more detrimental characteristics like a propensity towards heart disease. Although scientists have been studying genes and their relation to disease for decades, it wasn’t until enhancements in technology, especially the ability to map an entire human genome (Human Genome Project (HGP)), facilitated the growth of genetic testing. This voluntary testing identifies individual changes within a patient’s DNA compared to tons of other DNA sequences stored in databases. The HGP enabled us to determine genetic differences cheaper and faster than ever before. Now that we are capable of quickly sequencing entire genomes, we can identify disease causing mutations plus diversity in genes between individuals. These small, but meaningful differences can establish what individuals were present at a crime scene, for example. Or, whether you carry a cancer causing gene that could be passed to your children. Important decisions can be made based on our genetic material.
The goal in genetic testing is to find the inherited changes (mutations) that can infer different characteristics about a person in an assortment of situations such as: ancestry, disease susceptibility, forensics, and paternity. Many types of Genetic testing exist including: newborn screening, diagnostic testing, carrier testing, and predictive testing…..just to name a few. Predictive testing is extremely important due to the likelihood of finding a mutation that makes a person at risk for a certain disease. Knowing this information in advance (before the disease progresses or becomes a reality) could mean the difference between life and death for some people. In addition, another type of genetic testing in vogue nowadays is pharmacogenetics (PGx) testing, which is used for determining how an individual will respond to a particular medicine. Medications are metabolized in different ways depending on one’s genetic predisposition.
Advancements in genetic testing, particularly in the area of personalized medicine, has reached a point where there’s no need to leave the house. Direct-to-consumer (DTC) companies such as 23andMe started out revolutionizing the world of ancestry testing; however, the market for genetic testing isn’t far behind. It’s a fairly straight forward process. Once you receive the DTC kit after ordering online, you spit into a tube or swab your cheek, then send the sample back to the company and wait for results via an email. The reports provide insight into your genetics without clinically diagnosing with a particular disease. Having a clinical diagnosis is imperative for treatment, prevention, and/or reproductive concerns. Besides the insight you get from these results, you also have the option to allow companies like 23andMe to utilize your results for research purposes which could lead to more benefits and advancements in genetic testing. This is great for future understanding, but doesn’t typically permit immediate treatment since the purpose of research isn’t to diagnose. Keep in mind, there are privacy concerns to consider when consenting to research, an ongoing issue in genetic testing.
Another thing to take into account is that not all of the genetic variants 23andMe (and other DTC companies) report to consumers are FDA approved or intended for diagnostic purposes, but in early 2018 the company received FDA approval for the first DTC test for cancer risk without a prescription. Even though the DTC are convenient, due to the lack of regulation and diagnostic capability, some people still prefer obtaining results from a certified laboratory. This entails visiting the doctor and either requesting specific genetic testing or having a doctor’s recommendation for testing on account of family history, which is a common reason to agree to genetic testing. In this case, many sample types can be used to perform testing including: blood, hair, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. After the laboratory tests the sample, clinical results are sent to a person’s doctor or genetic counselor, or directly to the patient if requested. Whether you choose a DTC kit or a regulated laboratory depends on your goals and purpose for genetic testing. One thing is for sure….it’s great to have choices. As technology and knowledge continue to advance, more choices will be made possible.