March 29, 2021
Science

Genetic Disorders Vs Genetic Predispositions

See how the major DNA testing companies stack up!
By
Tomohiro Takano

If you don’t have an advanced degree in Genetics, it is not easy to sort out the differences between the major DNA health tests available on the market. Luckily for you, here at Genomelink, we believe that there is a perfect DNA test for every user.

But, in order to find the best DNA test, it is important that you know the difference between two very similar terms: genetic disorders vs genetic predispositions. This article will make sure you understand the difference between the terms. Then, we will dive into the different DNA testing companies to see which of these DNA health tests they offer!

Genetic Disorders vs Genetic Predispositions


If you have been researching DNA tests, you will know that there are 2 basic kinds of DNA health reports that are offered. Some reports are called “Carrier Status Reports” whereas the other tests are called “Genetic Health Risk Reports”. In this section, we will fully break down what each of those terms means.


Genetic Disorders and Carrier Status Reports


Carrier Status reports detail the genetic variants you carry that are related to genetic disorders. Genetic disorders, such as cystic fibrosis and Tay-Sachs disorder, are caused by DNA variants. Let’s take a look at cystic fibrosis to understand this better. 

Cystic Fibrosis is known as an autosomal recessive disorder. Autosomal means that it is carried on non-sex chromosomes (not your X or Y). Recessive means that one bad gene cannot cause the disease by itself. In recessive conditions, both of the genes that you received from your parents must be broken in order for you to get the condition. Some people carry one healthy version of the gene and one bad version of the gene. These people are known as “carriers”.

Carriers of the cystic fibrosis gene usually do not display any symptoms, but they still carry one faulty copy of the gene. Genes produce proteins, and in the case of a faulty gene, they produce faulty proteins. Carriers of the cystic fibrosis mutation produce both healthy and faulty proteins. Scientists have even determined that these proteins function as part of your mucous membranes. 


https://upload.wikimedia.org/wikipedia/commons/9/9a/Cysticfibrosis01.jpg


People with two faulty copies of the gene produce only faulty proteins. In cystic fibrosis, these faulty proteins do not do their job within each cell. This leads to the symptoms of the disease, such as the production of thick mucus in the lungs. The symptoms of the disorder are so drastic that you would certainly already know if you had two faulty genes. But, what if you only have one faulty gene?

That is where Carrier Status Reports come in.

Carrier Status Reports measure all of the most common mutations that can lead to a faulty gene. In a carrier status report, you will learn if you carry any of these mutations. This makes carrier status reports very useful in family planning and knowing which genes you might pass on to your children. Just check out this graphic!


https://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Autorecessive.svg/1350px-Autorecessive.svg.png


As you can see, two carriers of the cystic fibrosis mutation have a 1-in-4 chance of having a baby with cystic fibrosis. They also have a 1-in-4 chance of having a child with two healthy copies of the gene. The remaining 50% chance is having a child that is also a carrier. However, you may also find that neither you or your partner carry the mutation, in which case your child has a close to 0% chance of getting cystic fibrosis.

That makes Carrier Status Reports a very powerful tool for predicting and analyzing your risk for a number of diseases that science has proven are caused by your genes alone.


Now, let’s take a look at what a genetic predisposition is.

Genetic Predispositions and Genetic Health Risk Reports


While Carrier Status Reports have been around long before the time of at-home DNA testing, Genetic Predisposition reports are a product of the massive amounts of genetic data that have been collected via consumer DNA tests. To find Genetic Predispositions, scientists analyze what genetic variants people carry, and compare them to different diseases those same people end up getting. Instead of understanding the causation of the disease, these reports are simply reporting a correlation.

Put simply, a Genetic Health Risk Report says that if you carry a certain variant you are at a higher risk of getting a specific disease. However, unlike a carrier status test, it is not clear exactly how this gene may affect your body. Oftentimes, these genetic health risk reports have little-to-no understanding of why the genes are linked to disease. 

DNA testing companies offer a wide variety of genetic health reports, from cancer to high blood pressure. While this is valuable information and can help you understand your body better, you should know that for most of these conditions diet and exercise play a bigger role than your actual genes. 

Take the commonly advertised “Breast Cancer Genes”, BRCA1 and BRCA2. Many companies advertise that mutations to these genes can increase your chances of breast cancer by 80%!

While that number makes a great headline, most genetic testing companies do not tell you the whole story. The mutations that increase your risk by 80% are found only in a tiny minority of the population. Further, the BRCA genes may cause less than 5% of all breast cancer cases. So, even if you don’t carry the BRCA mutations, you still have the same risk as anyone else of getting breast cancer. You simply do not have an increased genetic risk. But, these facts don’t scare people into buying a DNA kit. 

That being said, Genetic Health Risk reports from sites like Genetic Genie are still very useful! If you know that you have a higher risk for certain diseases, you will be more likely to take action to counter your risk. This could mean going on a diet, creating a more regular exercise routine, or getting checked more commonly for the early signs of cancer or other diseases. 

Now, let’s breakdown the different Carrier Status Reports and Genetic Health Risk Reports offered by different companies!

DNA Companies by Carrier Status Reports and Genetic Health Risk Reports


23andMe

Carrier Status Reports: 40+ Reports

Genetic Health Risk Reports: 10+ Reports

23andMe, the first major company to offer at-home genetic testing, is still a leader in the amount and diversity of tests offered. 23andMe offers by-far the largest number of Carrier Status reports. These reports can be extremely helpful in family planning, as you and your partner can accurately estimate the risk of passing on certain diseases to your children with simple genetics.

As for the Genetic Health Risk reports offered by 23andMe, the same is true. Because 23andMe was one of the first companies to offer these tests, the Food and Drug Administration (FDA) was all over their initial offerings. Since then, 23andMe has made a massive effort to validate their findings and reports. What this means for consumers is that their tests are accurate and do not mislead consumers with their findings. You can read more about 23andMe in our full review of the company!


Ancestry

Carrier Status Reports: 3 Reports

Genetic Health Risk Reports: 6 Reports

Ancestry may have the largest number of DNA kit users, but they just recently got into the DNA health testing game. Therefore, the company only offers 9 total health-related DNA reports. While this may seem like a small number, the company does offer some of the most comprehensive ancestry analyses on the market. In fact, most of their DNA kit users seem to have come from their genealogy business.

However, if health reports interest you at all you may want to choose 23andMe or MyHeritage simply because these companies offer more health reports. If you like, you can check out our full review of Ancestry!


MyHeritage

Carrier Status Reports: 18 Reports

Genetic Health Risk Reports: 18 Reports

MyHeritage is similar to Ancestry in that it was primarily a genealogy company before at-home DNA kits became popular. Unlike Ancestry, MyHeritage expanded into DNA health testing much earlier. As such, MyHeritage can offer nearly 4-times the number of DNA health reports. Though 23andMe offers more carrier status reports, MyHeritage covers most of the “common” genetic disorders such as cystic fibrosis and Tay-Sachs. 

MyHeritage has slightly less specific ancestry results when compared with the other two companies here. However, they do have a massive historical records database that only Ancestry can compete with. So, if you are trying to build a family history and you are interested in DNA health traits, MyHeritage may fall just between the health-focused 23andMe kits and the ancestry-focused AncestryDNA kits. Check out more about MyHeritage in our full review!


Tomohiro Takano
Tomohiro Takano
Co-Founder and CEO