Our Traits reports explore how your DNA makes you unique, from cheek dimples to hair curliness. Most traits are influenced by many factors, both genetic and nongenetic, but some can be strongly predicted by the presence of just a few genetic variants. By analyzing survey responses of 23andMe customers who are genetically similar to you, we can use predictive models to provide you with your likelihood of having traits in common. You can help to fine-tune our models and assist in making interesting Trait reports in the future by consenting to research and answering survey questions.
Trait reports are distinctly different from the Carrier Status reports. In the Carrier Status reports, the variants we report on are well-understood and known to cause specific inherited conditions. In comparison, the variants used in our Trait reports don’t always cause the trait of interest, but show a strong statistical correlation with it. For some of these trait variants, we do know a little more about how they work, but for most, we are only beginning to learn how and why certain variants are linked to certain traits. Learn more about how Trait reports are different from Carrier Status and Wellness reports.
This article will cover:
- How to navigate your Trait reports
- Viewing and understanding your likelihood for a trait
- How Trait reports are different from Carrier Status and Wellness reports
Navigating your Trait reports
When you enter a Trait report category, you will be directed to the Index page. The Index provides easy navigation to each Trait report which displays your likelihood of possessing those traits.
In the example below, we are looking at the Facial Features report category which includes Trait reports on Cleft Chin, Cheek Dimples, Unibrow, Widow’s Peak, Eye Color, and Earlobe Type.
The Facial Features Trait report Category includes the following Trait reports: Cleft Chin, Cheek Dimples, Unibrow, Widow’s Peak, Eye Color, and Earlobe Type.
The Index page also includes information on what each report can and can’t tell you, and provides links to additional resources.
You can also navigate your Trait reports using the navigational menu located near the top of the page. By clicking on the topic tabs, you will be able to view the Trait reports associated with the topic and your likelihood of having each trait. The Scientific Details tab provides information on the scientific methods used to generate each report.
Viewing and understanding your likelihood of having a trait
By clicking on a topic, you will be able to view your likelihood of having or not having certain traits. Each Trait report includes two likelihood ring charts. The ring chart on the left represents you and shows your "genetic likelihood" of having certain versions of the trait, while the ring chart on the right shows how common the different versions of the trait are in 23andMe customers of your reported ethnicity.
Your genetic likelihood of having a certain version of a trait is determined by the proportion of 23andMe customers with different versions of the trait who also have a similar genotype as you. Your likelihood of having the trait (or not having it) is whichever proportion is over 50%.
In the example above, this customer is “not likely to have cheek dimples” because the majority (68%) of genetically similar customers do not have cheek dimples. On the other hand, 32% of customers with a similar genotype do have dimples.
Some traits are more complicated than simply having or not having the trait. Sometimes, you can have degrees of a trait such as with hair curliness. Because hair texture can range from straight to very curly, this trait is broken into six bins that span the texture range. To report your result, we combine the six bins into two big bins, one with straight to wavy hair, and one with big curls to very tight curls. Your genetic likelihood of having a particular hair texture depends on which bin adds up to over 50%.
In this example, 79% of customers with a similar genotype have straight to wavy hair, so we say, "you are likely to have straight or wavy hair" and show the trait breakdown of these genetically similar customers in the chart on the left. The chart on the right shows how common the different versions of the trait are overall, in 23andMe customers of your ethnicity or in all 23andMe customers. These percentages are calculated from customers who have answered survey questions about the trait.
By comparing the two charts side by side, you can see how your personal genetic likelihood for a certain hair texture is similar to or different from what would be expected for the average 23andMe customer of your ethnicity. If your genetic likelihood is similar to the overall likelihood for your ethnicity, it means your genetics predict a hair texture that is typical for a customer of your ethnicity. On the other hand, if your genetic likelihood is significantly different from the likelihood for your ethnicity, it means your genetics predict a hair texture that is less expected for the typical customer of your ethnicity. In other words, your likelihood of having a certain hair texture would be unique compared to other people of your ancestry.
Using our example above, Alison has a genetic likelihood of straight or wavy hair (79%) that is quite close to the 89% likelihood of straight or wavy hair in European ancestry customers; that means her genetics predict a hair type that is similar to what would be expected for a typical customer of her ethnicity. On the other hand, if Alison's genetic likelihood of straight or wavy hair was only 15% and her likelihood of curly hair was 85%, that would mean her genetics predict a trait that would be much less expected for the typical customer of her ethnicity. In that case, Alison could consider herself quite unique when it comes to the likelihood of curly hair in people of European ancestry.
How Trait reports are different from Carrier Status or Wellness reports
The Carrier Status reports* are about inherited conditions that are caused by specific variants in specific genes that are very well-studied. Therefore, these reports only include these specific variants. The evidence must be very strong for us to include a variant in a Carrier Status report, and if you have one of these variants then you are considered a carrier for that disease. All of our Carrier Status reports meet FDA criteria for scientific and clinical validity.
In contrast to the inherited conditions of our Carrier Status reports, most human traits are determined by many different factors, both genetic and nongenetic, which we do not yet fully understand. The variants we use in the Trait reports can be from published studies or from our own research using our database. The Trait reports are meant as a fun way to learn more about how genetics influences traits.
Wellness reports include topics that relate to lifestyle and healthy living. These topics can also be complex and influenced by many other factors, both genetic and nongenetic, similar to the Trait reports. Wellness reports can be based on variants that are published in peer-reviewed scientific studies, but may also include results based on statistical models or information from our own database.
*Our tests can be used to determine carrier status in adults from saliva collected using an FDA-cleared collection device (Oragene·DX model OGD-500.001), but cannot determine if you have two copies of the genetic variant. Each test is most relevant for people of certain ethnicities. The tests are not intended to diagnose a disease, or tell you anything about your risk for developing a disease in the future. On their own, carrier status tests are not intended to tell you anything about the health of your fetus, or your newborn child's risk of developing a particular disease later in life.