23andMe Cleared to Report 41 More BRCA Mutations

The U.S. Food and Drug Administration (FDA) has approved 23andMe, which makes at-home genetic tests, to report the presence of 41 more variants, or mutations, of the BRCA1 and BRCA2 genes that are linked to a higher risk of developing breast, ovarian, prostate, and pancreatic cancers.

Many of these added mutations are more likely to occur in Hispanic/Latino, Black and other populations that have been traditionally underserved by genetic testing.

Before this, 23andMe test results reported on only three BRCA1 and BRCA2 founder mutations that are most common in people of Ashkenazi Jewish (Eastern European) heritage.

A founder mutation is a specific gene mutation in a population that was founded by a small group of ancestors that were geographically or culturally isolated. Because the population was isolated, the rate of founder mutations in descendants is much higher than it would be if the population were larger and intermingling with more genetically diverse people.

Although the three founder mutations account for about 87% of BRCA1 mutations and about 93% of BRCA2 mutations in people of Ashkenazi Jewish descent, they make up the minority of BRCA mutations linked to cancer in people who are not of Ashkenazi Jewish descent.

So genetic counselors and other experts have been concerned that people without Ashkenazi Jewish heritage may get a false sense of security if the 23andMe test results show they don’t have a BRCA mutation.

From now on, 23andMe test results will report on 44 mutations in the BRCA1 and BRCA2 genes that are linked to a much higher risk of breast and ovarian cancer in women and breast cancer in men. The mutations also may be related to a higher risk of prostate cancer, pancreatic cancer, and other types of cancer.

People who had 23andMe genetic testing in the past will have access to the expanded BRCA mutation report once the company updates its platform. 23andMe said that people must specifically agree if they would like to receive information about whether they have any of the 41 new variants.

“In my opinion, it’s good news that 23andMe has elected to move forward with testing for more than just the three specific mutations that are commonly seen in individuals with Ashkenazi Jewish heritage,” said Rachel Brandt, PhD, a board-certified genetic counselor at Main Line Health in Pennsylvania. Dr. Brandt is also a member of the Breastcancer.org Professional Advisory Board. “This will increase the chances that people from all other ethnicities may receive a meaningful result from this test. It will also reduce the chances of people being misinformed by a negative result.

“While it is helpful [that] the list of specific mutations being tested by 23andMe has expanded, there have been over 3,500 mutations reported in these genes that are associated with increased cancer risk, so testing for only 44, while an improvement, is still limited,” Dr. Brandt added. “There is about a one in 400 chance in the general non-Ashkenazi-Jewish population for someone to have a BRCA mutation, and about a one in 40 chance in the Ashkenazi Jewish population, which is what prompted this testing to initially focus on those three mutations.

“There are many other genes that are also associated with increased risks for breast and other cancers that are not being tested by 23andMe. While 23andMe can be a helpful resource for identifying individuals with an elevated cancer risk, my recommendation is for more extensive, comprehensive testing of the entire BRCA1 and BRCA2 genes (not just for 44 specific mutations), as well as for other genes also related to breast cancer, for individuals with a personal or family history of breast, ovarian, prostate, and pancreatic cancer as per national testing guidelines.”