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Should I Believe What My DNA Tells Me?
What You Need to Know About Commercial DNA Tests
Post 1
Why My Ancestry May Not Be What My Genes Say It Is
May 14th, 2018
No matter what ethnicity or cultural ties you may have, commercial DNA tests are not as personalized as you’d think.
Additional sources of evidence are necessary to make any claims about your ancestry. Family history, surnames, and relation to historical figures are ways to fact check your DNA results. Skipping fact checking allows you to interpret your results any way you’d like, which can lead to some very far-fetched claims.
Your ancestry results often show the percentages of your genes that “originate” from a certain geographical region. The smaller the percentage, the more generations lie between you and that ancestor.
Genes are added to your family gene pool by every parent that came before you. But that’s not to say this pool doesn’t have a capacity limit. As time goes on, genes disappear as others take their place.
Sensitive topics like pillaging or colonizing ancestral groups should also be speculated. Many genes were spread widely by these seafaring groups, but it is also incorrect to assume that these genes lie within all of us. Records may suggest some relation to an infamous Viking, Conquistador, or other historical figure. But centuries of separation from such an ancestor could indicate that their genes have since been replaced by genes introduced in more recent generations.
One thing you do have control over, however, is how you will react if you do have an unexpected ancestor. It is definitely okay to be proud and speculate this heritage. It may even change the way you see yourself and the identity you emanate. However, it is important to do this responsibly and with sensitivity.
Black, Latin American, Native American, Middle Eastern, and Asian heritage is always an intriguing discovery as a white person. It is particularly important for white people to recognize that although they may have ancestors of color, there are some cultural aspects that have resulted from experiences white people will never fully understand. History is littered with terrible events that have threatened the lives and cultures of other ethnicities. Solidarity is the outcome of those experiences, so be aware that a person who is Caucasian may not be able to resonate with those experiences.
Remember, only you can decide to what extent you represent your heritage. But before you hang the national flag of an ancestor, double check to make sure that this person actually existed. Consult your family history to track down this ancestor. Genetic tests are not as accurate as you’d think.
You can also do your own research—find the specific regions your genetic testing company used to assign genes to those populations. Do these places match where your ancestors lived? Your family story may be unscientific, but that doesn’t discount it as a great source of evidence!
Just to be sure, get a second test from another source. Separate datasets only increase your chance of learning what your genes really say.
Image via Snopes.com
Post 2
Thoughts I Should Have After Viewing My DNA Health Results
May 14th, 2018
Image via NPR
The FDA has been keeping a close eye on 23andMe since 2010. As 23andMe only genotypes certain parts of specific genes, 23andMe is far from being able to predict the likelihood a customer will (or will not) develop a disease. This is not the company’s intent.
Disclosing medical information to the public is dangerous because disease risk is very complicated—even some doctors cannot correctly interpret genetic results surrounding disease. If you decide to participate in an at-home genetic test or have already done so, it is important to be informed.
Test results aren’t as personalized as you’d like to think. If you are concerned about your personal disease risk, seek help from a genetic consultant who can provide you with more information. Genetic counselors provide more personalized and in-depth examinations of your genes. They are the ones to go to if you are concerned about a disease, particularly one that runs in your family.
It is very important to talk to your family about diseases. Genes are complicated, and it often takes many abnormal genes to have a large effect on your risk of disease. Some genes are more obscure than others. DNA testing companies only focus on the common genes with a larger effect on disease risk, so commercial sources cannot accurately say what your chances are, and certainly are not equivalent to a diagnosis.
Unfortunately, more obscure genes have a smaller impact and are harder to detect, so it is important to talk to your family about disease trends. This can help you determine how much power genetics has over your chance of developing a disease.
Genes are not the only factor that influences your chances. Unhealthy habits change your body over the years and can increase your risk of disease. We all learn this at some point, but we don’t always consider seeing a genetic counselor early can help us make lifestyle choices to prevent diseases later on.
The point here? Do not rely solely on a commercial genetic test if you are concerned about developing a serious disease.
Last year, the FDA permitted 23andMe to test consumers for rare blood disease, late-onset Alzheimer's, and Parkinson’s disease. Now 23andMe has various disclaimers featured on their website and test results, which are seen by their consumers. They warn consumers of their tests’ limitations to prevent consumers from misunderstanding their results and taking dramatic measures. This is not to say that despite these limitations their results convey perfectly accurate information.
Although 23andMe has collected genetic ancestry information from all over the world, the majority of their information has been collected from large white American and Northern European samples.
This race bias in research exists for two reasons:
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Sweden’s public health system creates a nation-sized sample of white people for geneticists to study
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Researchers studying U.S. populations select white people in order to “limit” error in their results
As if people of color are genetically different than these white groups; I disagree. So does recent research.