THE PLOT THICKENS -ASHKENAZI BRCA GENE MUTATION FOUND IN SEPHARDIC JEWISH PEOPLE SUGGESTS THAT ALL JEWISH PEOPLE SHARE A SIMILAR GENOME
Jewish ethnic divisions refer to separate and someone distinctive Jewish communities. Most if not all of these resulted from the original Israeli diaspora. From there, Jewish people settled and mixed with local populations. Though Jewish people migrated to many areas in Europe and Asia, many eventually landed on the Iberian Peninsula (Sephardim) and to central Germanic Europe (Ashkenazim). In approximately the year 800, Iberia (Spain and Portugal) was conquered by the Moors, during which time Jewish people enjoyed excellent commerce with the Muslim World. It was also during this time that the Jewish people of central and northern Europe became more distant from the Iberian Jewish people developing their own language and traditions as well as moving eastward into Poland and other parts of eastern Europe.
Shortly after the BRCA1 and BRCA2 genes were sequenced in 1994-95, three founder mutations were found and attributed to the Ashkenazi Jewish ethnicity. In fact, the Ashkenazi panel was initially ordered specifically for those eastern European Jewish peoples with early onset breast cancer, ovarian cancer or a strong family history. Amazingly, within a few short years, Ashkenazi founder mutations were being found in Latinos from the southwestern United States.
In order to understand why this might be, it requires us to remember that the Inquisition began after the Moors were driven from Spain and Portugal in the latter 15th century. Jewish people were forcibly converted to Christians, and known as Conversos or Crypto-Jews. In response to the Inquisition, the diaspora from the Iberian Peninsula included movement to many parts of the Europe and Asia. However, it also included movement to Mexico and Latin America. As parts of northern Mexico became part of the USA, many Latinos were found to have to have Jewish genetic mutations.
Many have tried to determine the number of descendants of these Jewish people. In a world-wide multicenter study published in Nature Communications has shown that the descendants of Portuguese and Spanish Jewry is substantially higher than other studies have previously suggested. The results of this study showed that almost 25% of Latinos and Hispanics carry Jewish DNA!
So how does this impact breast cancer genetics? Certainly, one of the first founder mutations found in the BRCA genes was in the Ashkenazi (Eastern European and Germanic) Jewish people. In fact, Ashkenazi panels were created in the initial years of genetic testing. What is now clear is that these founder mutations do not only apply to Ashkenazi Jews but also to Sephardic (Spanish) and Mizrahi (middle eastern) Jews. In most instances marginal patients are not tested or allowed extended screening (MRI etc.) unless noted to be “Jewish”. There are approximately 59 million Hispanics in the United States, 25% of which contain Jewish DNA. Moreover, the NCCN has extended testing recommendations to all Ashkenazi Jews. It is obvious that many Hispanics are currently denied extended surveillance or genetic testing. It is important that all of these Jewish groups, Ashkenazi, Sephardic, Mizrahi and Hispanics be treated equally when it comes to offering extended surveillance and genetic testing.