7 Things to Know About Jewish Genetic Diseases

Becca Bakal and Rabbi Peter E. Kasdan

Genetics may seem complicated, but even simple messaging can go a long way toward informing members of the Jewish community, especially when it comes to genetic disorders that are more common among Jews than in the general population. Such disorders include Canavan disease, Gaucher disease, and others – as well as hereditary cancers, including those related to BRCA gene mutations.

Although Tay-Sachs disease used to top the list of Jewish genetic diseases, as a result of rigorous awareness and testing campaigns in the Ashkenazi community going back to the 1970s, as detailed in this JTA article, “the incidence of Tay-Sachs has fallen by more than 90 percent among Jews, thanks to a combination of scientific advances and volunteer community activism that brought screening for the disease into synagogues, Jewish community centers and, eventually, routine medical care.”

At the same time, both science and the Jewish community look vastly different than they did in the 1970s. Scientific knowledge – particularly in the field of genetics – has grown exponentially over the decades, and researchers are constantly uncovering new information about how to interpret the results of genetic screening tests and reduce related risks. Furthermore, as a result of intermarriage, conversion, worldwide immigration, and other factors, the Jewish community is more genetically diverse than at any time in the past. Even so, Jewish genetic diseases still occur among Ashkenazi Jews, the majority of North America’s Jewish population.

As a community health educator and a rabbi, respectively, we believe it is our responsibility to deliver the Jewish genetic diseases message to each new generation of young people and into the public arena, where it can truly make a difference.

With that responsibility in mind, we offer you seven important things to know about Jewish genetic diseases.

1. People with no family history of Jewish genetic disorders can be at risk.

As many as one in four people of Jewish ancestry – both Ashkenazim (originally from central and eastern Europe) and Sephardim (from the Middle East, North Africa, and the Iberian Peninsula) – carries an altered gene responsible for at least one Jewish genetic disease. Having an altered gene related to a disease means they are at risk of passing that genetic disease to their children. Jewish genetic diseases that are prevalent within the Sephardic community are largely dependent on carriers’ countries of origin.

Carriers are generally healthy and likely have no way of knowing the potential risk to their family. Although carriers are not usually affected with symptoms of the disease, if both members of a couple carry an altered gene for the same disease (estimated to be about three percent of Ashkenazi Jewish couples), with each pregnancy they have a 25 percent chance of conceiving a child with that disease, which are known as autosomal recessive disorders. There are large panels of autosomal recessive Ashkenazi Jewish genetic diseases, many of which, to date, have no treatment or cure.

Unlike the Jewish genetic diseases noted above, early onset torsion dystonia – a painful, disabling disease – is an autosomal dominant disorder, which means it may be passed down to a child even if only one parent carries a mutation for it. With each pregnancy, these couples have a 50 percent chance of conceiving a child at risk of having early onset torsion dystonia. Like many of the others, there is no known cure for this condition.

2. Genetic counseling and screening can help families assess their risk.

Jewish genetic diseases are not exclusive to the Jewish community; these diseases also occur in the general population but at lower carrier rates. Therefore, genetic counseling and carrier screening for diseases in both the Ashkenazi and Sephardic communities are vitally important – whether the potential parents are Ashkenazim, an interfaith couple, a same-sex couple, one that includes a Jew-by-choice, or a single person of either gender using artificial insemination, a surrogate, or other technology to achieve pregnancy. 

If health insurance doesn’t cover the costs of counseling and screening, many organizations offer these services for Jewish genetic diseases and for those that occur in all populations. Subsidies and financial assistance options are often available for those without health insurance.

3. The best time for genetic counseling and screening is before pregnancy.

Genetic counseling, in person, by video conference, or over the phone, is a critical component of the genetic testing process for both medical and psychological reasons. Unfortunately, the counseling component often is overlooked, testing is not always routinely ordered by physicians, and when it is ordered, doctors may not be ordering tests for the full complement of diseases.

4. There are effective tools to manage genetic risk.

Couples that find they both are carriers of altered genes for the same condition have a variety of options available to them that will allow them to start a healthy family together. One such advanced reproductive technology is preimplantation genetic testing (PGT), which, as part of in vitro fertilization, biopsies early embryos and selects ones without the condition for implantation.

5. We all play a role in sharing information about Jewish genetic health.

There are important ways we all can protect and preserve the health of our Jewish community. Put Jewish genetics on the educational agenda at both a community and individual level. When speaking with newly engaged or newly married congregants, take the opportunity to inform them about carrier screening – a critical aspect of family planning for Jewish and interfaith couples. Ask your synagogue and other Jewish organizations to include resources on their websites and bulletin boards to direct families to more information.

6. There are many resources providing information and support around Jewish genetic health.

Even if you feel you don’t know enough to share information about Jewish genetic health, there’s no need to be an expert. You can support your community and its members just by sharing resources. A variety of organizations exist to educate about Jewish genetic health risks, offer subsidized screening, and support individuals living with Jewish genetic disorders. Among them are:

Many people feel that discussing Jewish genetic health can be “scary.” Indeed, there may be challenges when discussing genetic health in the Jewish community, but there also are opportunities for starting those important conversations and reframing them to demonstrate that genetic information can be empowering and, indeed, lifesaving. 

7. Breast cancer isn’t a Jewish genetic disease, but…

The presence of a BRCA gene mutation is not synonymous with having a specific disease, but rather with one’s personal lifetime risk for developing certain cancers, most commonly breast (in both men and women) and ovarian cancer, as well as prostate and pancreatic cancer, and melanoma. The prevalence of BRCA mutations among Jewish people of Ashkenazi descent is estimated to be approximately one in 40, which is 10 times greater than in the general population. BRCA mutations can dramatically increase lifetime risk of cancer in both men and women. In couples in which one partner is a known mutation carrier there is a 50 percent chance, with each pregnancy, of conceiving a child who also will carry the mutation.

Testing for BRCA and an increasing list of other hereditary cancer mutations has never been more accessible, but genetic counseling with a certified genetic counselor is an important step that should precede testing. The process can be expensive, but the cost continues to drop. What’s more, individuals of Ashkenazi Jewish ancestry often qualify for insurance coverage when a family history of cancer warrants counseling and testing. Risk management strategies include enhanced screening, medication, and/or risk-reducing surgeries. Preimplantation genetic testing, too, is an option for BRCA mutation carriers.

For more information about hereditary cancer mutations and managing the associated risks, visit Sharsheret, FORCE: Facing Our Risk of Cancer Empowered, or Yodeah, a relatively new initiative focused on education and facilitating cost-effective testing for BRCA and other hereditary cancer-causing genetic mutations for individuals of Ashkenazi descent. To find a genetic counselor near you in the U.S. or Canada, visit the National Society of Genetic Counselors.

Sadly, Jewish genetic diseases will not go away anytime soon. Rather, scientists likely will continue to discover many more in the years ahead. Our critical work, then, to raise awareness about these diseases and the availability of counseling and testing must go on. Learning about genetic risk can be intimidating, but it is also empowering. The more information we have, the more we can do to protect our health and that of our families and those in the Jewish community.