Arelis Esther Martir-Negron, MD, on Prevalence of BRCA Variants in Hispanic Residents of South Florida

Since the early to mid-90s, we have known about the BRCA1 and BRCA2 mutations. We have not had enough data for certain populations in the Hispanic population. We know fairly well about the Mexican population because there have been studies. But for the South Florida population, which is mainly Cuban, Caribbean Cuban, and also now includes South American populations, we don't have enough data. In our study of almost 4,000 people tested, the majority were of Hispanic population based on our diverse population in South Florida. Of these, almost 40% were of Cuban descent, and in the Cuban population specifically, genetic testing is not happening as it should, and it's very important to know more about this population. It also included individuals from Venezuelan, Puerto Rican, Dominican Republic, and Colombian descent, among others. The admixture there is different from what we see in the southwest part of the United States, which is mostly Mexican, a combination of Spaniard and Amerindian descent. In our population, there is an admixture of three races: Spaniard, African, and Amerindian descent. There is also some Portuguese because we saw patients from Brazil. What we found is three novel mutations—mutations that have not been identified in the population before. We also saw something very interesting: a founder mutation of Icelandic and Finnish descent in individuals that were notable, and this was in eight individuals of Cuban descent who were not related. We also found a mutation that is common in the Portuguese population. We saw some Ashkenazi Jewish population, but not as high as in the Mexican population. Why is this important? Because we need to diversify the data. We have data about Ashkenazi Jewish and Northern European descent. And if we don't get more information, we can make mistakes in interpretation. Interpretation is very important because we can make the mistake of calling something pathogenic when it's really a variant of uncertain significance. Also, it's important for coverage. If we know about founder mutations, it's possible that insurance will cover the test. It's also important because eventually, when we learn more, we can do genotype-phenotype correlation—that is, knowing a particular mutation, what are the cancers that are associated—and maybe we can avoid overtreatment, unnecessary surgeries, and potentially reduce the need for screening. We are planning to do more with our data. We're going to be looking at other genes because, as you know, there are more genes associated with cancers. BRCA1 and BRCA2 are only two of many, and the majority of the patients had panel testing, and we're also going to be looking at patients with other types of cancers.