Most services offer the user one or more of three testing options. Autosomal DNA testing samples DNA from both maternal and paternal lines, although it can’t distinguish which genes come from which parent. Y-DNA testing traces DNA on the Y chromosome, meaning genetic traits that are passed down from father to son will show up on this test. For example, the famous Cohen Modal Haplotype (CMH), a Y-chromosome cluster of six markers common to men who are Kohanim, has been traced to common ancestry dating 3,000 years ago. Similar clusters exist for Leviim. The third test, for mtDna (mitochondrial DNA), traces descent through the female line of the family.

Sarina Roffe recommends FTDNA to her clients; she’s been using it for at least ten years. She believes they have the largest group of Jewish users; hence a Jewish user is more likely to get a hit in terms of finding family. “It’s not about the testing per se; it’s about the people the company has in the database,” she counsels. “FTDNA has been around for a long time. They go to all the Jewish genealogical conferences and have a presence in the community.”

Unfortunately, the various services don’t share data. “It’s a Tower of Babel,” laments Miriam Kairey, another genealogist who divides her time between New Jersey and Brooklyn. “The cropping up of different companies is a disservice to everyone, because they don’t share the information.” On the other hand, some companies, like FTDNA, do permit users to take the data they receive and share it with other companies.

Miriam recommends that male users searching for roots employ FTDNA. “They have a Y-chromosome analysis to allow men to see the family ‘pedigree,’ the male attributes passed down from father to son,” she says. “Men should also use their Family Finder feature to connect to people with similar autosomal [overall] genetic profiles.”

As for women, she says she prefers the 23andMe service, which used to provide users with genetic information about a wide range of health conditions, such as caffeine sensitivity, propensity to celiac disease, and breast cancer. “Doctors would charge $3,000 for those tests — the services are much cheaper,” she says. “Having that information can be a matter of life and death.”

But software engineer and genealogist Jaim Harlow told Mishpacha that the FDA forced 23andMe to stop testing for genetically based health conditions in 2013. “They had the American Medical Association up in arms, because they had no doctors on staff,” he says. “People like me who got in early were lucky; we got a full sequencing.” As of 2015, the FDA decided to allow 23andMe to run 36 tests that indicate carrier status for various diseases in clients’ offspring, and four “wellness” indicators like lactose intolerance — a far cry from the original 240-plus health conditions originally tested for.

The Athletigen company provides individualized health profiles based on genetic testing, geared to helping athletes improve their performance, and is based in Canada. But the possibilities for using genetic profiling to boost health and longevity have so much commercial potential the US government may not be able to suppress broader usage for very long. While working on this article, I heard a radio ad for the “NJ Diet” in Clifton, New Jersey, which claims to use genetic testing to create tailor-made diets for people. I called for more information, and while they do have a doctor overseeing the operation, no one called back.

The Limits of DNA Testing

Genetic testing provides only one piece of the ancestry puzzle; the whole picture can only be reconstructed by documents or oral histories. “DNA proves there’s a relationship,” says Sarina, who specializes in the Sephardic community. “But it’s up to the genealogist to figure out the hows and whys of the connection.”

An example: Miriam Kairey found that her own DNA matched with members of a family by the name of Helouani in Buenos Aires. “My maiden name is Sasson, but my grandfather once happened to tell me we originally had a double name, Sasson-Helouani,” she relates. “If he hadn’t passed on that piece of information, I wouldn’t have had a starting point to trace the connection.”

DNA helps genealogists narrow down the field when many people share a common surname (think Cohen or Dweck). Sarina once worked with two different families named Sutton, a name that can be non-Jewish as well as Jewish. She suspected the families were related. When DNA tests proved they were indeed a very close DNA match, she showed the results to each side. Through the families’ input, she was able to reconstruct the missing family link.

There are challenges for each Jewish subpopulation. “In the Ashkenazic world, it’s important to know which shtetl your family came from,” Miriam says. “The European towns kept censuses and other records. But a Jew who comes from Iraq can’t go back there to search. Even if he could, he probably wouldn’t find anything.”

Syrian Jews have traditionally been very careful to preserve family names, so even a child taken in by another family would keep his father’s last name. That makes their family history easier to trace. But Sephardic Jews have a more diverse gene pool than Ashkenazim, who grew from a much smaller original population. “Ashkenazic genes are very specific and easy to identify,” she says. “But 20 percent of Ashkenazic Jews have Sephardic ancestry, although it has gotten diluted over the past 500 years.”

I asked how a Syrian Jew would know if his family is Sephardic — i.e., originally came from Spain — or from the Eidut Hamizrach (e.g., neighboring Iraq). Miriam didn’t have any genetic evidence, but was able to find her own family’s origins through records from the 1600s. “It seems that the Jews who arrived in Syria from Spain didn’t pray with the Jews who were there already,” she says. “They had their own minyan.”

She adds that no DNA link has yet been shown for families who claim to be descended from Dovid Hamelech. Nor have they been discovered for families like Tawil who have a mesorah that they descend from Eli Hakohein.

Miriam’s enthusiasm is contagious; she thinks everyone could benefit from genetic testing. “I’m always finding surprises in my work,” she says. “Sometimes I feel like there’s a Hand guiding me as I sift through the material — I’ll come across things I wasn’t originally looking for.”

Another person bitten by the ancestry bug is Jaim Harlow, who lives in Palo Alto. He has been working for years to reconstruct his family history — a real challenge, given that his family has circumnavigated the globe. His Portuguese ancestors ended up in Belarus, and then migrated to the Caribbean. Working on the historical side, he discovered that diplomat Don Yosef Nasi (a nephew of Dona Gracia Mendes-Nasi) negotiated trade deals with Poland, and his agents set up havens for Sephardic Jews in towns throughout southern Poland, western Ukraine, and eastern Romania. From Romania or Poland, Harlow’s relatives ended up in Belarus. (Harlow hired a researcher to go through archives in Krakow to substantiate these premises.)

Harlow used every DNA-testing service available to trace his genetic profile. In the process, he discovered a relative in Kazakhstan who matched him at the level of a third cousin. His newfound relative, whose last name is Harlap, is now helping him reconstruct the family history (“He does the genetic analyses, I do the moldy paper part,” Harlow jokes). Jaim has gotten so fascinated by DNA testing that he now serves as a curator for Geni.com, another DNA testing service, and is participating in an investigation of the genetics of the Jews of Kaifeng.

My Turn

Reading about DNA testing certainly whet my curiosity to try it out myself. Bennett Greenspan, the president and founder of Family Tree DNA, graciously offered to send us a test.

Shortly afterward, a small packet came in the mail with cotton swabs, vials, and instructions even I could follow. A few cheek swabs later, the return packet was ready to be dropped into the mailbox. Then the waiting game began; it takes up to two months to get results.

As far as I know, my family is pretty typical of American Jews; my grandparents were born in Eastern Europe and came to the US as children in the early 20th century. I’d always assumed we were 100 percent chicken-soup-and-gefilte-fish Ashkenazim.

Of course, I did once run into a lady in the cooking aisle of Amazing Savings who told me she was three-quarters Sephardic, and much of that was Romanian. “Romanian?” I said. “My grandfather was from Romania, but I don’t think he was Sephardic.”

“Did he eat mamaliga?” she said.

My mother has often said that her father adored mamaliga, and I told the woman as much.

“Then he was Sephardic!” she cried triumphantly. “Mamaliga was really polenta. The Italian Sephardim brought it to Romania.”

“I think my mother would be surprised to hear that,” I said.

But my curiosity was piqued and when I started researching this article, I found my grandfather’s very Ashkenazic-sounding name, Weintraub, on a list of Romanian names of Iberian origin. As Jaim Harlow had mentioned, groups of Sephardim settled in Romania after the Inquisition.

About a month after I submitted my DNA, I received a strange e-mail. “My name is Javier C., from Majorca,” it said. “We are an exact match on the mtDNA test and my family are descendants of Chuetas, Majorcan Jews. I must say, we do not get more than 2–3 matches a year! Majorca is a small island in the Mediterranean, and Jews were there since before the Romans.”

Since I hadn’t received any notification of my own DNA results yet, I thought this sounded pretty fishy. But then I got another e-mail from someone in Tucson, Arizona, with a more regular-sounding Jewish name (let’s call him Josh Levine). He said we were a match, and he already knew about the man in Majorca. “My maternal family was in Spain and North Africa and possibly because of the Spanish Inquisition ended up in Eastern Europe,” Josh said.

I logged on to FTDNA and found out that only my mtDNA (mitochondrial DNA, or DNA passed directly through the maternal line) had been analyzed so far. I was part of a genetic group called ROa2m, which traces back to the Middle East thousands of years ago. Bennett Greenspan confirmed: “We ran two different tests on you,” he explained. “Your mtDNA is Semitic, meaning it was likely deported by the Romans 2,000 years ago, or from some other depopulation of our part of the Fertile Crescent.”

Well, duh. But it was also kind of thrilling, in the same way it was thrilling the first time I went to the Kosel and saw living proof of the Temple, to find substantiation for my Jewish roots in my very own DNA. I called Josh Levine, since he seemed to have spent a lot of time researching our haplogroup. “Our genetic group is very small and unique. We’re considered a relic,” he said. “We’re one of the few that descend directly to the ancient Israelites.”

I felt an odd surge of pride in this proof of my pure Jewish lineage, since mtDNA is strictly passed mother to daughter (men receive it from their mothers, but don’t pass it on). Apparently there have been few or zero female converts along my family’s path. As much as I love and respect all my convert friends, I have to admit to having felt like a Harry Potter character who just found he’s pure wizard stock instead of a Mudblood.

I checked my list of mtDNA matches and found I had matches all over the world, Ashkenazic and Sephardic. Some weren’t even Jewish, like a lady from Ecuador who knew her family descended from Jews from Toledo, Spain.

A few weeks later my “Family Finder” data, based on both maternal and paternal DNA, came in. I received e-mails from several people who had seen the matches (I allowed my e-mail to be shared), and I tried e-mailing some other matches myself. But nobody in the database seemed to be a really close match to me. Nor was I able to establish any clear family relations to any of the people I was in touch with. Many of them said things like, “I’ve heard of those names and towns, but today there’s no one left to ask.” One said, “I remember the names of the towns — Bialystok, Lvov, Yekaterinoslav — being mentioned, mainly by my father, who came to the US when he was eight. I don’t recall the context or connection. Wish I did, but back then I didn’t care!”

The bottom line was that FTDNA didn’t produce any long-lost cousins, at least not so far. I called Sarina Roffe for advice. “If you’re looking for roots, the genetic tests will narrow down the field of people who could be your family, especially if you have a common surname,” she said. “It can help direct your research. But for women, the tests are often overrated. They give a clearer picture for men because they show the Y chromosome groups as well.”

FTDNA keeps results on file for 25 years, and lets you know when new matches appear. So there’s still hope that one day I’ll be reunited with some long-lost cousins (hopefully rich and generous ones). And now, when new acquaintances innocently ask my Moroccan husband if I come from Casablanca or Marrakech, maybe I’ll tell them I have family in Majorca.

The Personal is the Political

While genetic testing is a boon for those needing to discover lost roots — adoptees, Jews whose family history went up in smoke during the war, estranged relatives — it also has the potential to be used for less innocuous ends. In a post-Hitler era, the prospect of being able to identify Jewish blood through DNA testing — or the ancestry of any other “undesirable” group, for that matter — certainly gives pause. Dr. Harry Ostrer, the author of Legacy: A Genetic History of the Jewish People, has written, “The study of Jewish population genetics is potentially fraught with peril… on the one hand, the study of Jewish genetics might be viewed as an elitist effort, promoting a certain general view of Jewish superiority. On the other hand, it might provide fodder for anti-Semites by providing evidence of a genetic base for undesirable traits that are present among some Jews.”

Jewish genetics have already been brought to bear on the “Who Is A Jew?” question. According to Ian V. McGonigle and Lauren W. Herman in the Journal of Law and the Biosciences (2015), the Israeli government has announced that it would begin using genetic tests to determine whether potential olim are Jewish. The decision came about as a result of the huge influx of people from the former Soviet Union, some of whom were not halachically Jewish.

The Law of Return was amended in 1970 to include converts, descendants of Jewish fathers but not mothers, and people with a Jewish grandparent, as candidates for Israeli citizenship. “The Prime Minister’s Office attempted to distinguish the purpose of the DNA test as a secular immigration regulation rather than a marker of religious identity,” write McGonigle and Herman, quoting the Office’s declaration: “We’re not talking about a test to determine Jewishness. We’re talking about a test to determine a family bond that entitles aliyah.”

In other words, carrying Jewish genes isn’t enough to make one Jewish. Dr. Ostrer writes, “Jews can be said to be a people with a shared genetic legacy, although not all Jews share the same genes, nor is having a part of that legacy a requirement for being Jewish.”

But genetic testing does shed some light on the claims of various groups to Jewish ancestry. The Lemba people of southern Africa claim descent from a tribe of Israel through the paternal line and observe some laws of kashrus and other Jewish customs. While the maternal line may not be Jewish, geneticist Mark Thomas reports in the American Journal of Human Genetics (2000) that “the CMH [Cohen modal haplotype, or genetic marker for Kohein status] appears in the Lemba with a frequency similar to that in the general Jewish population (in just under one out of every ten men).” Dr. Ostrer’s book states that the Lemba and India’s Cochin Jews share genetic ancestry with Jews from North America and Europe, as well as Middle Eastern and Yemenite Jews; however, the Bene Israel of India and the Ethiopian Jews do not share these links. For Ostrer, this indicates they converted to Judaism rather than being direct descendants of Jews.

Genetic testing has also served to debunk some false claims about Jewish origins. In 1976, Arthur Koestler wrote The Thirteenth Tribe, claiming that Jews were descended from the Khazars; in 2008, Shlomo Sand expanded the thesis into The Invention of the Jewish People. Both books were bestsellers and both sought to discredit Jewish claims to Eretz Yisrael (although both were roundly disputed by most scholars). Today, Ostrer says, we don’t need ancient documents or archeology to prove them wrong: the genetic evidence clearly shows the Jewish people do not descend from pagan Eastern Europeans and Eurasians. In fact, our Middle Eastern origins mean we share more DNA clusters with Israel’s Arab population.

Genetic testing can also enlighten those non-Jews, often from Hispanic backgrounds, who suspect they have Jewish roots. A 2008 New York Times article reports that almost 20 percent of the population of Spain and Portugal appears to have Sephardic ancestry; another 11 percent show ancestry from the Moors. Miriam Kairey’s husband found himself genetically linked to a man in Guatemala who wasn’t Jewish, but knew he was of Spanish rather than native extraction, and whose family had left a town that was known to make life difficult for conversos.

You can have Jewish genes and not be Jewish; you can have non-Jewish genes and be Jewish through conversion. Judaism is much more than an ethnicity; our history of moves, integration of converts, and assimilation into native populations means we carry a complex cocktail of genetic spirits. Given all that, the miracle is that we’re still as closely related as we are.

Timeline: The History of DNA Testing

1856–66: Gregor Mendel, working with pea plants, developed the idea of “dominant” and “recessive” traits that were passed down through generations in predictable ways. The importance of his ideas remained dormant — “recessive,” if you will — for 30 years.

1869: Swiss chemist Friedrich Miescher, searching for protein components in white blood cells, finds a substance he calls “nuclein” in the nuclei, with high phosphorus content and other unusual properties. “Nuclein” was DNA. Again, it would take 50 years before the scientific community recognized the importance of this finding.

1900s: As Mendel’s work is rediscovered, the Eugenics Movement — the idea to “improve” the human race by breeding superior species — gains traction.

1902: Sir Archibald Garrod, an Oxford-trained physician, is the first to link Mendel’s theories with a human disease, taking family histories of patients with the disease alkaptonuria.

1944: Oswald Avery, an immunologist at the Hospital of the Rockefeller Institute for Medical Research, isolates DNA.

1952-53: Rosalind Franklin photographs crystallized DNA fibers, leading to Watson and Crick’s discovery of the double helix structure of DNA.

1961: Chaim Sheba, Surgeon General of the IDF and Director of the Israeli Ministry of Health, organizes a conference on Jewish genetics and their relationship to disease resistance.

1965: Marshall Nirenberg sequences the genetic code — the means by which nucleotide bases are transformed into proteins by the body’s cells.

1983: Huntington’s disease is the first genetic disease to be mapped.

1990: The BRCA gene for hereditary breast/ovarian cancer syndrome is discovered. The Human Genome Project to map all 3.2 billion letters in the human genetic code begins.

1997: The Y chromosome haplotypes for Kohanim is found by Karl Skorecki and his team in Haifa.

2003: The Human Genome Project is completed.

Sources for Historical Family Research (from the Jewish Genealogical Society):

• American Jewish Joint Distribution Committee (JDC) Archives
• Center for Jewish History
• Genealogy Indexer
• International Association of Jewish Genealogical Societies (IAJGS)
• Italian Genealogical Group
• Jewish Records Indexing-Poland (JRI-Poland)
• JewishGen
• JewishGen Yizkor Book Project
• Jewish Genealogy Society of Long Island
• Jewish Genealogy Society of North Jersey
• Museum of Family History
• Museum of Jewish Heritage
• One-Step Webpages by Stephen P. Morse
• Yizkor Books Online — New York Public Library

The Jewish Genealogical Society also publishes how-to research books, workbooks and genealogical guides specific to many Eastern European countries.