Specific genetic variants in the BRCA1 and BRCA2 genes are associated with an increased risk of developing certain cancers, including breast cancer (in women and men) and ovarian cancer. These variants may also be associated with an increased risk for prostate cancer and certain other cancers. This test includes three genetic variants in the BRCA1 and BRCA2 genes that are most common in people of Ashkenazi Jewish descent.
AncestryDNA, 23andMe, HomeDNA, Living DNA, and MyHeritage DNA all provide reports of your ethnicity, some showing maps of where your ancestors lived along with information about the particular countries and regions. National Geographic goes further back, pinpointing where in Africa your ancestors came from and tracing migration patterns through to near-present times. It's less about your personal genetic makeup and more about who your ancestors were and how you're connected to the beginning of civilization.
Similarly, mitochondrial DNA, or mtDNA, is used by direct-to-consumer DNA tests to trace your direct maternal lineage and determine maternal haplogroups. While most DNA lives in your cells' nuclei, mtDNA lives in the mitochondria. Mitochondria are the cells' powerhouses – their 37 genes are necessary for cellular energy production and respiration. Previous research suggested that mtDNA is inherited directly from your mother, but a recent study found that biparental mtDNA may be more common. This discovery may affect maternal haplogroup testing in DNA tests in the future, but for now, it’s safe to assume your results are correct.
Even though we are all unique, most of our DNA is actually identical to other people’s DNA. However, specific regions vary highly between people. These regions are called polymorphic. Differences in these variable regions between people are known as polymorphisms. Each of us inherits a unique combination of polymorphisms from our parents. DNA polymorphisms can be analysed to give a DNA profile.
When we speak, co-founder Hamish Grierson describes Thriva as “a lifestyle brand with medical-grade testing at the back end”, an opportunity for “people to see themselves as consumers rather than patients”. Grierson gives examples of people who have benefited from Thriva testing, sometimes picking up early on serious issues. As for alarming people, Grierson says that Thriva has on-site facilities to discuss results and is intended to be “complementary to the NHS” rather than replacing it: “If there are questions we can’t answer, we’re very clear that people should pick it up with their GP.”
A genetic counselor, a healthcare professional with special training in genetic conditions, will be able to answer your questions and help you make an informed choice. We recommend that you speak with a genetic counselor before testing, and also after testing to help you understand your results and what actions you should take. This is especially important for health conditions that are preventable or treatable.
The situation is made even more complex if it is considered that three or more people may have contributed to a particular DNA result. Often, in such cases, it is not possible for a scientist to undertake a reliable statistical evaluation of the mixed DNA result. If the DNA result indicates that a very low level of DNA has been detected, it is recommended that the reporting forensic scientist consider the possibility that the result may have been derived from a very low level of DNA from more than one person, some of the components of which may be missing from the DNA result because of the low level of DNA present
As with traditional genealogical research, DNA testing can provide surprises so be prepared for the unexpected. You might uncover family secrets by matching with a cousin or a half-sibling that you didn’t know existed. Conversely a relation who is expected to share DNA with you might turn out not to be a genetic relative at all. In rare cases, people discover that their parents are not their biological parents. For a good overview of the ethical implications of DNA testing see the Genetic Genealogy Standards.