How Do Sephardic Jews Figure Into The Genetic Equation?

By Schelly Talalay Dardashti

Published August 25, 2006, issue of August 25, 2006.
  • Print
  • Share Share

When Hispanic women in Colorado’s San Luis Valley were shown to carry a high frequency of the Ashkenazic breast-cancer gene, some genetic experts began to wonder.

Subsequent investigations showed that the women in question were likely the descendents of conversos fleeing the Inquisition, who settled in the region late in the 16th century.

A number of recent scientific studies have shown that illnesses long thought to occur only among Ashkenazic Jews can be found among Sephardim as well. Such findings, experts say, may alter not only how individual genetic disorders are viewed but also the very notion of the “Jewish genetic disease.”

A recent Tel Aviv University study, along with others conducted in Colorado and Montreal, has shown that the BRCA1 “Ashkenazic” breast-cancer mutation began to appear before the Jewish people’s major exiles and diasporas. The identical mutation appears in Ashkenazim and Sephardim, indicating an ancient common founder.

The marker has been found in Mizrahim (Jews from North Africa and the Middle East) and among Hispanics in Los Angeles and other cities. It also appears in Spain, Chile, Turkey, Yemen, Iraq, Morocco, Greece, Iran, Pakistan and Egypt — all lands with histories of Jewish migration.

And the breast-cancer mutation is not alone among genetic illnesses previously thought to be unique to Ashkenazic Jews.

Bloom’s syndrome has been found in Chile, Costa Rica, Mexico, El Salvador and the southwestern United States, although those who tested positive have denied Jewish ancestry. In a heavily Catholic country, such a response may still be a form of protection against persecution.

Because 90% of American Jews are of Ashkenazic descent, it is safe to assume that non-Ashkenazic populations have been underrepresented in studies, according to Dr. Harry Ostrer, the director of the human genetics program at the NYU Medical Center.

“It’s an important question that should be asked,” said Dr. Susan J. Gross, a co-director of the division of reproductive genetics at the Montefiore Medical Center, in New York. “Looking at this issue beyond the Ashkenazi community is of vital importance, and is not merely an academic exercise. Advancing our knowledge in this area can be of major significance to a much broader spectrum of Jewish women beyond this particular group.”

Authors of a study on Parkinson’s disease among Ashkenazim readily admit that the number of non-Ashkenazim they have studied is extremely small.

Dr. Laurie Ozelius and Dr. Susan Bressman, both of Yeshiva’s Albert Einstein College of Medicine, said that they want to obtain control samples from non-Ashkenazic groups.

“Our study reported a higher frequency in Ashkenazim because we had more Ashkenazi patients. North Africans also had a high frequency, but except for one Sephardic individual there were few non-Ashkenazim tested.”

The two suspect the disorder to be just as common in non-Ashkenazi Jewish populations as it is among Ashkenazim. Being able to see a few hundred Sephardic and Mizrahi individuals, they said, could “change the entire picture.”

“We won’t know until we get samples,” Bressman said. “We need to get many samples and look at many diseases with diverse ancestry in mind.”

In their small sample, Ozelius said, she found cases in Spain, Portugal, Italy — all seemingly following Jewish migration paths.

“By looking at inbred or isolated populations, we can find new genes and understand new diseases,” Bressman said. “Whether common genes are shared or not, this is an entire group of diverse Jews which needs to be investigated.”

In Boston, Dr. Daniel M. Laby, an assistant clinical professor of ophthalmology at Harvard Medical School, brings more than just a physician’s training to the table. Laby is also a genealogist with 13th-century documents on his Sephardic family, Laby de la Cavalleria.

“If you are going to talk to people, especially Jews, about breast cancer, you also need to be up on background and history,” he said, adding that it isn’t correct to say that a gene is only Ashkenazic when it is Jewish. “It’s bordering on malpractice not to inform those who may be of non-Ashkenazi origin.”

In Laby’s view, a thorough knowledge of Jewish history and immigration should be required of genetic counselors.

Further complicating matters is the fact that that some who today identify as Ashkenazim may really have been Sephardim who migrated to Eastern Europe 500 years ago.

Jewish genealogists and academic researchers are discovering Sephardim among Eastern European ancestors.

Today, researchers aware of such factors are actively looking for ways to involve non-Ashkenazi Jewish populations in various studies.

“We really need both genealogy and DNA on all these communities — it is imperative,” Bressman said. “Genealogists and geneticists must work together and this will result in a wealth of science.”

Schelly Talalay Dardashti, a native New Yorker now living in Israel, served for a number of years as the Jewish genealogy columnist for The Jerusalem Post.

Find us on Facebook!
  • This is what the rockets over Israel and Gaza look like from space:
  • "Israel should not let captives languish or corpses rot. It should do everything in its power to recover people and bodies. Jewish law places a premium on pidyon shvuyim, “the redemption of captives,” and proper burial. But not when the price will lead to more death and more kidnappings." Do you agree?
  •'s Allison Benedikt wrote that Taglit-Birthright Israel is partly to blame for the death of American IDF volunteer Max Steinberg. This is why she's wrong:
  • Israeli soldiers want you to buy them socks. And snacks. And backpacks. And underwear. And pizza. So claim dozens of fundraising campaigns launched by American Jewish and Israeli charities since the start of the current wave of crisis and conflict in Israel and Gaza.
  • The sign reads: “Dogs are allowed in this establishment but Zionists are not under any circumstances.”
  • Is Twitter Israel's new worst enemy?
  • More than 50 former Israeli soldiers have refused to serve in the current ground operation in #Gaza.
  • "My wife and I are both half-Jewish. Both of us very much felt and feel American first and Jewish second. We are currently debating whether we should send our daughter to a Jewish pre-K and kindergarten program or to a public one. Pros? Give her a Jewish community and identity that she could build on throughout her life. Cons? Costs a lot of money; She will enter school with the idea that being Jewish makes her different somehow instead of something that you do after or in addition to regular school. Maybe a Shabbat sing-along would be enough?"
  • Undeterred by the conflict, 24 Jews participated in the first ever Jewish National Fund— JDate singles trip to Israel. Translation: Jews age 30 to 45 travelled to Israel to get it on in the sun, with a side of hummus.
  • "It pains and shocks me to say this, but here goes: My father was right all along. He always told me, as I spouted liberal talking points at the Shabbos table and challenged his hawkish views on Israel and the Palestinians to his unending chagrin, that I would one day change my tune." Have you had a similar experience?
  • "'What’s this, mommy?' she asked, while pulling at the purple sleeve to unwrap this mysterious little gift mom keeps hidden in the inside pocket of her bag. Oh boy, how do I answer?"
  • "I fear that we are witnessing the end of politics in the Israeli-Palestinian conflict. I see no possibility for resolution right now. I look into the future and see only a void." What do you think?
  • Not a gazillionaire? Take the "poor door."
  • "We will do what we must to protect our people. We have that right. We are not less deserving of life and quiet than anyone else. No more apologies."
  • "Woody Allen should have quit while he was ahead." Ezra Glinter's review of "Magic in the Moonlight":
  • from-cache

Would you like to receive updates about new stories?

We will not share your e-mail address or other personal information.

Already subscribed? Manage your subscription.