Genetic testing is nothing short of a miracle of modern science. That being said, most people overestimate what genetic information can actually tell you. Some people even go so far as to believe that DNA testing from 23andMe is some sort of medical analysis. This article explains that while a genetic risk test can be informative, it is far from a medical analysis.
What Does a Genetic Test Actually Test?
23andMe, in addition to most other genetic testing companies, test single-nucleotide polymorphisms (SNPs). Called “snips”, these individual pieces of DNA can signal the presence of a particular genetic variant. To learn more about SNPs, read this blog post. SNPs are related to various genetic diseases, are correlated with other disease risks, and can determine traits such as eye color and lactose intolerance.
Can a Genetic Test Diagnose a Disease?
In certain rare cases, genetic data can diagnose the presence of a disease. However, this is only for hereditary, or genetic, disease. For example, in the case of an autosomal recessive disorder, the symptoms of the disease are seen in any person with two disease-carrying variants for a particular gene. The variants typically cause the gene not to function, which causes certain cells to not function properly.
The thing is, if you have a hereditary disease, you have likely known about it since birth. Diseases like cystic fibrosis, hereditary hemochromatosis, and hereditary thrombophilia often have symptoms from birth soon after. So, using a 23andMe test to diagnose a hereditary disorder is not that helpful. However, 23andMe can tell you if you are a “carrier” of certain diseases. This information can usually be found in your family history, but a consumer genetic test can tell you as well.
This means that instead of 2 bad copies of a gene, you inherited 1 good copy and 1 bad copy. While your cells can still function on the 1 good copy and you don’t show any symptoms, you can still pass the bad copy onto your children. If your carrier status report says you carry a disease-causing allele, you can consult a genetic counselor before having children to discuss what risk your children may have.
What a Genetic Test Cannot Do…
Outside of carrier status reports on diseases that are known to be caused genetically, all other genetic risk reports are simply detailing your health risk for certain diseases. However, this information can never be used as a medical analysis, or as a method of diagnosing a non-genetic disease. Diseases like Late-Onset Alzheimer’s disease, Celiac disease, breast cancer, and Parkinson’s disease may have genetic influences, but they are not caused by genetics. On the other hand, hereditary diseases are caused by genetics directly.
As such, a genetic test can only estimate your health risk for a number of different conditions, based on the genes you carry. This is in no way a diagnosis of the disease. In fact, you may never get the disease, especially if you decrease your risk through diet and exercise.
What a Doctors Considers That DNA Tests Do Not
Genetic information found in your saliva sample only gives a laboratory your DNA sequence. From this sequence, the laboratory can determine your risk factors for some health conditions. But, DNA analysis is far from a diagnosis from a doctor.
Doctors look for symptoms of a disease for diagnosis, not just a higher risk factor. Doctors use health information such as your heart rate, levels of enzymes in your blood, and many other factors to diagnose complex issues like heart disease or macular degeneration. In other words, insurance companies will not cover a 23andMe test as a legitimate diagnosis. If a 23andMe test shows that your personal genetic markers are worrisome, you should see your healthcare provider to understand how this risk assessment will impact you, if at all.
Is a DNA Test Actually Useful?
Yes! DNA testing is a great way to better understand how your genetic code may impact your life. While it cannot be used to diagnose a disease or replace a proper medical analysis, the information it can provide is expanding every day. Many companies even offer additional analysis for free, which you can access simply by uploading your raw data to their sites. These sites can give you additional health risk information, as well as lifestyle wellness reports and ancestry information! Check it out!
Know "More" About Your DNA Data
1. Genomelink — FREE
2. Promethease (genetic health risk)
3. Family Tree DNA (FTDNA) — FREE
4. MyHeritage DNA — FREE
5. LivingDNA — FREE
6. GEDmatch — FREE
Nutrition and Fitness
To find out more, go to the updated list of uploading websites here!