A geneticist and rabbi find our Jewish mothers embedded in our DNA 

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n these days of sophisticated DNA research, is it possible to establish Jewish lineage with a simple cheek swab? Leading geneticists have discovered that the special genetic sequences transmitted exclusively from mother to child might be a key to tracing Jewish identity inherited through the maternal line. And Rabbi Zev Litke, a dayan specializing in family research, is already using the evidence to enhance claims of Jewishness in rabbinical courts

When a well-known Swiss entertainer decided to take one of the many newly-popular and affordable DNA tests, he was so enthusiastic about discovering his family history that he opted to announce the results live on his television show. While his parents emigrated from Turkey 50 years ago and he identifies with his Turkish-Muslim ancestry, he was in for a shock: When he opened the envelope in front of a live audience, the results showed that although he’s 15/16 Turkish-Muslim, he’s also 1/16 Jewish. And not just Jewish, but Ashkenazi Jewish. That means the Jewish strain in his family went back just four generations.

His identity might have been seriously upended, but today, the ability to authenticate Jewish ancestry has taken on a new urgency, especially among the Eastern-European immigrant community in the Holy Land. In Israel, the Law of Return grants near-automatic citizenship to immigrants with at least one Jewish grandparent, but the chief rabbinate only recognizes them as Jews if they have a Jewish mother. These two differing qualifications leave many immigrants in limbo: According to the State, they are considered Jewish and are listed as such on government forms. But according to the Rabbinate, they cannot marry in Israel or be buried in a Jewish cemetery unless their halachic Jewishness is confirmed.

For the many immigrants who did not arrive from established Jewish communities that could attest to their members’ Jewishness, obtaining authentication is often impossible. Additionally, often the documents presented are either smudged originals, blurry photocopies, or forgeries. The result is often frustration, pain, dashed hopes, and no little resentment.

But in these days of sophisticated DNA research, is there an easier way of corroborating family ties than sifting through dusty prewar archives? What if a Jewish connection, and more specifically, a maternal one, could be verified with a simple cheek swab?

Backward Link

Five years ago, a select group of scientists on the cutting edge of genetic population studies met with senior dayanim in Jerusalem to discuss this very question. The rabbanim were looking for a solution to help the thousands who couldn’t prove their Jewish origins but still claimed Jewish maternal ancestors. The dayanim included Rav Zalman Nechemia Goldberg ztz”l; Jerusalem posek, rosh yeshivah, and author of the Minchas Asher series Rav Asher Weiss; Rav Yehoram Ulman, head of the Sydney beis din; Rav Yisrael Barenbaum, head of the Moscow beis din; and Rav Zev Litke, a talmid of Rav Weiss who had been part of Rav Yosef Fleischman’s beis din in Jerusalem. The scientific team was led by Professor Karl Skorecki, a Canadian-born nephrologist and genetic researcher at Rambam Medical Center, who in 1997 identified the “Kohein” gene, the genetic markers shared by Kohanim who trace their ancestry to Aharon HaKohein.

The focus of Professor Skorecki’s newest study was mitochondrial DNA, which unlike nuclear DNA, is transmitted exclusively from mother to child — perfect for tracing Jewish identity as it is inherited through the maternal line. He discovered that within certain populations, there are typical genetic markers in the DNA of the mitochondria specifically — and particularly among Jewish communities — and these markers link back to a small subgroup of women who came to the European continent from the Middle East. Over the years, this population has accumulated genetic markers that distinguish it from other populations of the world.

Working with Eastern European population databases, the researchers found that certain mitochondrial DNA sequences could be found in a meaningful percentage of the Ashkenazi Jewry sample, while they are nearly absent among non-Jewish European populations. That means that in many cases, it’s possible to identify whether the mother or maternal grandmother of the person in question descends from a Jewish gene pool.