What is Jewish about BRCA?

How common are BRCA gene mutations? 

In the general population, BRCA gene mutations occur in approximately 1 in 250 people 

However, in the Jewish population this is much higher: 

  • Around 1 in 40 people in the Ashkenazi population have a BRCA gene mutation 
  • Around 1 in 140 people in the Sephardi population have a BRCA gene mutation  

Despite this prevalence, a staggering majority of Jewish people with a BRCA mutation do not know they have one.


89% of individuals of Jewish individuals who have a BRCA gene mutation are undetected and therefore entirely unaware of their status

Why are BRCA gene mutations more commons in the Jewish population? 

BRCA gene mutations, and in fact mutations in several other genes, are more common in the Jewish population compared to the general population. But why? 

The likely reason for this is a phenomenon called the Founder Effect. This occurs when a small group of individuals leaves a larger population to form a new isolated community. They leave either out of choice or due to factors out of their control such as natural disasters or even persecution. 

Simply by chance, the new community will contain different proportions of genetic traits compared to the original larger population. This is dictated simply by which individuals left to form the new population.  

Certain traits may be less common, and certain traits may be more. These traits may be benign, such as eye or hair colour, or more serious like having a BRCA gene mutation.  When the new community grows over time into a large population the new proportions are perpetuated and if the community stays isolated the proportions will be sustained.   

Throughout Jewish history there have been many opportunities for the founder effect to occur. These include repeated persecutions and forced migrations. In addition, Jewish communities have kept themselves reproductively isolated from surrounding populations and this has helped to maintain their distinct genetic make-up.  


What does this all mean for me?

Put simply it means that if you have Jewish ancestry (1 Jewish grandparent or more) you have an increased risk of having a BRCA gene mutation. In turn, these mutations increase your risk for developing several types of cancer. Fortunately, the risks for developing these cancer types can be managed if you are aware that you have the mutation. 

BRCA gene testing enables you to find out if you do or do not have a BRCA gene mutation, and therefore if you do or do not have an increased risk for some types of cancer. Should you be found to have a mutation, risk management advice and interventions are available on the NHS. These are designed either catch cancer earlier when the prognosis is often better or even prevent it from developing all together. 

Overall it means that as a Jewish individual you should be aware of your BRCA mutation risk and should understand the role, benefits and implications of BRCA testing. All this is important so that you can responsibly consider if and when to get tested. 

‘’But I thought that…‘’ 

There are many misconceptions surrounding BRCA and Jewish people. Below are some of the most common Jewish BRCA myths. Click the arrows to reveal the corresponding Jewish BRCA facts.

This is incorrect. Anyone with 1 or more Jewish grandparent has an increased risk for BRCA gene mutation  

In fact, all Jewish subgroups i.e., Ashkenazi, Sephardi, Mizrahi etc, are more likely to have a BRCA gene mutation compared to the general population. This means testing is relevant for non-Ashkenazi Jews too

Anyone with Jewish ancestry, irrespective of their affiliation or observance, has an increased BRCA mutation risk 

Research has demonstrated that all Jewish people, even those with no cases of breast or ovarian cancer in their family history, have an increased risk of having a BRCA gene mutation. Up to 60% of those carrying a BRCA mutation may not have a strong family history of cancer.