If you’re here, it may be because your genetic sex from DNA analysis is different than your self-reported sex. There are many reasons this can happen, and we want to provide you with some information on how 23andMe uses your genetic sex and your self-reported sex to tailor your account experience.
This article will discuss the following topics:
- Why does 23andMe need to know my sex?
- How is my self-reported sex used?
- How is my genetic sex used?
- Sharing and privacy considerations
- I have a genetic condition that affects my sex chromosomes
Why does 23andMe need to know my sex?
23andMe uses one’s self-reported sex and genetic sex in a few important ways. One way we use this information is as a part of our quality control steps. Providing accurate data is a top priority. If someone’s self-reported sex doesn’t match what we’ve determined from our analysis of their DNA, we want to make sure nothing has gone wrong.
We do understand that sex is not always binary, and that "male" and "female" don't reflect the full spectrum of possible genders. However, our reports are based on scientific studies done primarily in 46,XX and 46,XY individuals who are cisgender. As new research is conducted, we hope that we'll be able to provide more tailored information to our intersex and transgender customers.
How is my self-reported sex used?
We use your self-reported sex to help us interpret your results for certain topics, and to provide you with content that applies to you. For example, genetic risks and what they mean may differ between men and women. If you tell us you are female, your reports will contain information that is relevant to genetic females (XX). If you tell us you are male, your reports will contain information that is relevant to genetic males (XY).
Additionally, some of our reports (such as Male Hair Loss and Bald Spot) cover traits that are sex-specific. We determine whether you receive these reports based on your self-reported sex.
Keep in mind that you can always change the self-reported sex in your profile from within your Account Settings.
How is my genetic sex used?
Genetic sex is the sex 23andMe determines from your DNA analysis, based on genetic markers on the sex chromosomes (X and Y). As we are a DNA service, the sex chromosomes can sometimes be important for us to consider in a few of our reports. One of our Ancestry Reports, called a Paternal Haplogroup Report, can only be directly generated for an individual with a Y chromosome.
Additionally, our Ancestry Composition Report displays a chromosome painting to show where each ancestry assignment is from on a chromosomal level. For people who were determined to be genetically female, there will be two X chromosomes shown in this report, whereas genetically male individuals will only see one X chromosome.
Please keep in mind that the genotyping technology we use to analyze your sample is not designed to pick up genetic changes beyond the types of single variant changes we include in our reports. 23andMe will assign you a sex based on your DNA analysis. It is important to note that our genotyping service is not designed to identify intersex conditions even though they may become apparent in individuals that are genotyped by our service. Additionally, 23andMe is neither a diagnostic tool nor a substitute for a physician’s advice. If your primary concern is to identify your genetic sex, we recommend you consult with a genetic counselor.
Sharing and privacy considerations
We recognize that individuals have different comfort levels when sharing personal information with other 23andMe users, and have designed our service to give customers control over how much information they share. While your genetic sex is never shared directly with individuals with whom you may be sharing or in the DNA Relatives feature, there are some sex-specific features that could allow others to infer your genetic sex.
The DNA Relatives feature is an interactive 23andMe feature that allows you to find and connect with genetic relatives who are also 23andMe users participating in this feature, and to learn more about your family story. This feature is optional; other 23andMe users will not be able to see you as a genetic match unless you opt in to the feature.
If you choose to participate in the DNA Relatives feature, your profile will be shown in your matches' DNA Relatives list. Your visible profile will include the following information:
- Your profile sex (Male/Female)
- Your haplogroup assignment(s)
- Your predicted relationship with that person (i.e. brother, cousin, distant relative)
For a full list of the information that will displayed in DNA Relatives, review our Privacy and Display Settings in DNA Relatives help article.
Your Profile Sex (Male/Female)
Your profile sex is your self-reported sex, which is associated with the profile. While your profile sex was originally selected during the registration process, you can update it at anytime within your Account Settings.
Your Haplogroup Assignment(s)
The DNA Relatives feature automatically displays your haplogroup assignment(s) to your matches. The paternal haplogroup assignment is defined by variants found on the Y chromosome. A genetically male customer will receive a paternal haplogroup assignment, but a genetically female customer will not receive an assignment unless she has a father or brother genotyped by our service.
While the presence of a paternal haplogroup assignment is not necessarily an indication of genetic sex, your matches may be able to infer your genetic sex based on the presence or absence of this report.
Your Predicted Relationship
The DNA Relatives feature estimates a predicted relationship and range using the number of segments and percent DNA shared. In some cases, such as predicting a brother or sister, your self-reported profile sex may also be used to predict a relationship.
It is important to note that your genetic sex is never used to predict a relationship. Additionally, 23andMe does not show a Y chromosome comparison in any of our sharing features, regardless of a customer’s sex.
I have a genetic condition that affects my sex chromosomes
The 23andMe Personal Genetic Service analyzes your DNA at specific points throughout your genome where single letters of the genetic sequence have been shown to differ among individuals. This process is called SNP genotyping, and is not well-suited for detecting most chromosomal abnormalities, such as Turner syndrome (45,X) and Klinefelter syndrome (47,XXY).
The vast majority of 23andMe Carrier Status* and Health Predisposition* Reports are based solely on genes located in chromosomes 1-22 (not the sex chromosomes). Thus, these reports should not be impacted by any sex chromosome abnormality.
However, our test does look at variants on the X chromosome for one of our Genetic Health Risk reports (G6PD Deficiency**) as well as for our Ancestry Composition Report. If you have questions about how your genetic condition will impact these reports for you, please reach out to our Customer Care team.
*The 23andMe PGS test includes health predisposition and carrier status reports. Health predisposition reports include both reports that meet US FDA requirements for genetic health risks and the 23andMe Type 2 Diabetes health predisposition report which is based on 23andMe research and has not been reviewed by the FDA. The test uses qualitative genotyping to detect select clinically relevant variants in the genomic DNA of adults from saliva for the purpose of reporting and interpreting genetic health risks and reporting carrier status. It is not intended to diagnose any disease. Your ethnicity may affect the relevance of each report and how your genetic health risk results are interpreted. Each genetic health risk report describes if a person has variants associated with a higher risk of developing a disease, but does not describe a person’s overall risk of developing the disease. The test is not intended to tell you anything about your current state of health, or to be used to make medical decisions, including whether or not you should take a medication, how much of a medication you should take, or determine any treatment. Our carrier status reports can be used to determine carrier status, but cannot determine if you have two copies of any genetic variant. These carrier reports are not intended to tell you anything about your risk for developing a disease in the future, the health of your fetus, or your newborn child's risk of developing a particular disease later in life. For certain conditions, we provide a single report that includes information on both carrier status and genetic health risk. For important information and limitations regarding each genetic health risk and carrier status report, visit https://www.23andme.com/test-info/. The G6PD Deficiency genetic health risk report is indicated for reporting of the Val68Met variant in the G6PD gene and describes if a person has a variant associated with G6PD deficiency and an increased risk for episodes of anemia. The variants included in this report are best studied in people of African descent.