With the advent of online ancestry DNA testing, and advancements in genetic screening for various medical aliments, we’re able to know more than ever about the genes that make us who we are.
But is there a point to knowing we’re 25% Irish? And is there a point to knowing we could one day be struck down with a disease we’re unable to prevent?
We asked five experts if we should consider a DNA test.
Four out of five experts said yes.
Here are their detailed responses.
Yes, but only if you understand and accept all the risks, the benefits are important enough, and you have competent specialist support. Risks include:
- Inaccurate findings.
- Genetic risks that might never eventuate.
- Findings about diseases you can do nothing about.
- Findings that you weren’t expecting (for example about parentage).
- Findings that may affect relatives who may not want to know.
- The use of genetic information to your detriment, for example by employers, governments, health insurers.
- Crossovers between forensic and scientific databases that could implicate you in a crime.
Consider DNA testing if you meet criteria that recommend screening (like age or family history), you have symptoms that suggest a genetic cause (even if only to exclude it), and there is some realistic therapy available. Given the complexity of the issue, each case should be carefully considered. Not all DNA tests are equal, necessary, or even useful.
Yes, so long as you know the implications, limitations, and risks involved. Genetic testing can save lives, assist with disease prevention, answer diagnostic questions, provide insights into medication responses, and be a tool for discovering ancestry information. Genomic technology is advancing rapidly and the increase in genomic understanding is breathtaking. But genetic testing isn’t a crystal ball, is not determinative of all health outcomes, and isn’t always reliable.
There are many types of genetic tests, and you need to understand what a specific test can and can’t tell you. Further, there are implications of learning your genetic information, such as discrimination by life insurers and privacy implications, which you need to be aware of. If the genetic testing is accurate and reliable, the results will be explained to you by a genetics professional. If you understand and have thought through the limitations and risks, testing may be beneficial.
Yes, knowledge is power. Genes don’t determine who we are — but they play an important part. Genetic testing can tell you whether you are at risk of disease, like some breast or bowel cancer, and you can take steps to prevent it. Or if you can’t, say you find you are at increased risk of dementia, you can make career, family, retirement, and other plans around the reality of your own life, not some imagined fiction. You can choose to use prenatal or embryo testing to have children who don’t have the same risks as you, or others.
Ancestry testing uncovers your broader family and shows how linked we are to people all over the world. In the future, polygenic testing will give better estimates of talents and personality, the opportunities and constraints on our lives. Power can be used for good, or misused. Genetic testing requires understanding and proper counseling. And genetic knowledge can be used to restrict freedom. But it can be liberating —freedom is choosing to set your own rules within the limits of your life.
Genetic testing is incredibly powerful in the right situations. If you have symptoms of a genetic disorder, testing can pinpoint the cause. If you have a family member with a genetic condition, testing can identify if you are at risk. For example, if your parent has a mutation in a cancer gene you can be tested, and if you have the mutation you can take steps to detect or prevent cancer.
Carrier screening can provide couples with information about potential genetic conditions in future children; reproductive options including IVF are available to avoid having a child with those conditions.
What about broad testing in the absence of any of the above scenarios? Such testing can be useful but needs to be approached with caution. Do you want to know if you have a mutation that means you will develop Alzheimer’s disease in your 40s or 50s and for which there is no preventive treatment?
No, not unless you are very convinced the company providing the test is reputable and can give you accurate information underpinned by scientific evidence. Be wary of how companies market their tests — some of their claims are very overstated. And many companies interpret the same result differently, which is worrying. This can be the case for tests marketed for ancestry, characteristics such as personality, as well as for medical, including health and wellness. Usually it’s because the evidence from different studies is not always the same, as we don’t yet know enough about all the DNA variations in our genome.
Someone with medical symptoms should consult a doctor, who can order DNA tests if necessary or refer on. While ancestry DNA testing can tell you about genetic relatives, much of the information about percentage ethnicity is too variable and often not useful. It’s also important to consider the terms and conditions under which you mail your sample to a company — they might onsell your DNA data.