by Rabbi Yaakov Kleiman

The fascinating story of how DNA studies confirm an ancient biblical tradition.

Dr. Karl Skorecki, a Cohen of Eastern European parents, was attending synagogue one morning. The Cohen called up for the Torah reading that morning was a Jew of Sephardic background, whose parents were born in North Africa.Dr. Skorecki looked at the Sephardi Cohen’s physical features and considered his own physical features.They were significantly different in stature, skin coloration and hair and eye color. Yet both had a tradition of being Cohanim, direct descendants of one man — Aaron, the brother of Moses.

Cohanim (plural of Cohen) are the priestly family of the Jewish people, members of the Tribe of Levi.The books of Exodus and Leviticus describe the responsibilities of the Cohanim, which include the Temple service and blessing of the people. The Torah (the first five books of the Bible) describes the anointing of Aaron, the brother of Moses, as the first High Priest (Cohen Gadol).
Jewish tradition, based on the Torah, is that all Cohanim are direct descendants of Aaron, the brother of Moses. The Cohen line is patrilineal — passed from father to son without interruption for 3,300 years, or more than 100 generations.
Dr. Skorecki considered, “According to tradition, this Sephardi Cohen and I have a common ancestor. Could this line have been maintained since Sinai, and throughout the long exile of the Jewish people?” As a scientist, he wondered, could such a claim be tested?

Being a nephrologist and a top-level researcher at the University of Toronto and the Rambam-Technion Medical Center in Haifa, he was involved in the breakthroughs in molecular genetics which are revolutionizing medicine and the study of the life-sciences. He was also aware of the newly developing application of DNA analysis to the study of history and population diversity.
Dr. Skorecki considered a hypothesis: if the Cohanim are descendants of one man, they should have a common set of genetic markers — a common haplotype — that of their common ancestor. In our case, Aaron HaCohen.

A genetic marker is a variation in the nucleotide sequence of the DNA, known as a mutation. Mutations which occur within genes — a part of the DNA which codes for a protein — usually cause a malfunction or disease and is lost due to selection in succeeding generations. However, mutations found in so-called “non-coding regions” of the DNA tend to persist.
Since the Y chromosome consists almost entirely of non-coding DNA (except for the genes determining maleness), it would tend to accumulate mutations. Since it is passed from father to son without recombination, the genetic information on a Y chromosome of a man living today is basically the same as that of his ancient male ancestors, except for the rare mutations that occur along the hereditary line.

A combination of these neutral mutations, known as a haplotype, can serve as a genetic signature of a man’s male ancestry. Maternal genealogies are also being studied by means of the m-DNA (mitrocondrial DNA), which is inherited only from the mother.

Dr. Skorecki made contact with Professor Michael Hammer, of the University of Arizona, a leading researcher in molecular genetics and a pioneer in Y chromosome research. Professor Hammer uses DNA analysis to study the history of populations, their origins and migrations. His previous research included work on the origins of the Native American Indians and the development of the Japanese people.

A study was undertaken to test the hypothesis. If there were a common ancestor, the Cohanim should have common genetic markers at a higher frequency than the general Jewish population.

In the first study, as reported in the prestigious British science journal, Nature (January 2, 1997), 188 Jewish males were asked to contribute some cheek cells from which their DNA was extracted for study. Participants from Israel, England and North America were asked to identify whether they were a Cohen, Levi or Israelite, and to identify their family background. The results of the analysis of the Y chromosome markers of the Cohanim and non-Cohanim were indeed significant. A particular marker, (YAP-) was detected in 98.5 percent of the Cohanim, and in a significantly lower percentage of non-Cohanim.

In a second study, Dr. Skorecki and associates gathered more DNA samples and expanded their selection of Y chromosome markers. Solidifying their hypothesis of the Cohens’ common ancestor, they found that a particular array of six chromosomal markers was found in 97 of the 106 Cohens tested. This collection of markers has come to be known as the Cohen Modal Hapoltype (CMH) — the standard genetic signature of the Jewish priestly family. The chances of these findings happening at random is greater than one in 10,000.

The finding of a common set of genetic markers in both Ashkenazi and Sephardi Cohanim worldwide clearly indicates an origin pre-dating the separate development of the two communities around 1000 CE. Date calculation based on the variation of the mutations among Cohanim today yields a time frame of 106 generations from the ancestral founder of the line, some 3,300 years — the approximate time of the Exodus from Egypt, the lifetime of Aaron HaCohen.

Professor Hammer was recently in Israel for the Jewish Genome Conference. He confirmed that his findings are consistent — over 80 percent of self-identified Cohanim have a common set of markers. The finding that less than one-third of the non-Cohen Jews who were tested possess these markers is not surprising to the geneticists. Jewishness is not defined genetically. Other Y-chromosomes can enter the Jewish gene pool through conversion or through a non-Jewish father. Jewish status is determined by the mother. Tribe membership follows the father’s line.

Calculations based on the high rate of genetic similarity of today’s Cohanim resulted in the highest “paternity-certainty” rate ever recorded in population genetics studies — a scientific testimony to family faithfulness.

Stated Dr. David Goldstein of Oxford University:
“For more than 90 percent of the Cohens to share the same genetic markers after such a period of time is a testament to the devotion of the wives of the Cohens over the years. Even a low rate of infidelity would have dramatically lowered the percentage.”
[Science News, October 3, 1998]

Wider genetic studies of diverse present day Jewish communities show a remarkable genetic cohesiveness. Jews from Iran, Iraq, Yemen, North Africa and European Ashkenazim all cluster together with other Semitic groups, with their origin in the Middle East. A common geographical original can be seen for all mainstream Jewish groups studied. This genetic research has clearly refuted the libel that the Ashkenazi Jews are not related to the ancient Hebrews, but are descendants of the Kuzar tribe — a pre-10th century Turko-Asian empire which reportedly converted en masse to Judaism. Researchers compared the DNA signature of the Ashkenazi Jews against those of Turkish-derived people, and found no correspondence.

In their second published paper in Nature (July 9, 1998) the researchers included an unexpected finding. Those Jews in the study who identified themselves as Levites did not show a common set of markers as did the Cohanim. The Levites clustered in three groupings, one of them the CMH. According to tradition, the Levites should also show a genetic signature from a common paternal patrilineal ancestor. The researchers are now focusing effort on the study of Levites’ genetic make up to learn more about their history in the Diaspora.

Using the CMH as a DNA signature of the ancient Hebrews, researchers are pursuing a hunt for Jewish genes around the world.
This could have ramifications in the search for the Biblical Ten Lost Tribes. Using the genetic markers of the Cohanim as a yardstick, these genetic archaeologists are using DNA research to discover historical links to the Jewish people.

The researchers’ policy is that the research is not a test of individuals, but an examination of the extended family. Having the CMH is not a proof of one’s being a Cohen, for the mother’s side is also significant in determining one’s Cohen status. At present, there are no ramifications in Jewish law due to this discovery. No one is certified nor disqualified because of their Y chromosome markers.

The research has shown a clear genetic relationship amongst Cohanim and their direct lineage from a common ancestor. The research findings support the Torah statements that the line of Aaron will last throughout history:

“… and they shall have the Priesthood as a statute forever, and you shall consecrate Aaron and his sons.” [Exodus 29:9] “… it shall be for them an appointment to an everlasting Priesthood throughout their generations.” [Exodus 40:15] “And it shall be to him and to his descendants after him a covenant of everlastingPriesthood.” [Numbers 25:13]

That our Torah tradition is supported by these findings is an inspiration for many that God surely keeps His promises. May we soon see the Cohanim restored to their service, Levites on their Temple platform and Israelites at their places.

If you are a Cohen or Levi interested in participating in the DNA research and/or receiving further information please contact:
Center For Cohanim,
3 Rehov HaMekubalim,
Old City, Jerusalem, Israel
Phone/Fax: (02) 628-9243

Thanks to Professor Edward Simon, microbiologist at Purdue University, lecturer and board member of the Association of Orthodox Jewish Scientists, for his expert input.
Author Biography:
Rabbi Yaakov HaKohen Kleiman is a lecturer at Aish HaTorah, Jerusalem, specializing in Temple studies. He is co-director with Rabbi Nachman Kahana, of the Center For Kohanim.

4 thoughts on “The Cohanim – DNA Connection

  • I hope the U.S.A. will stop supplying Israel with weapons and missles to kill
    their own blood related Jewish people in other countries. In ancient Bible history
    the Jews went to Mesopotamia and Babylon which is now Iraq and the Jews went to Persia which is now Iran and the Jews went to Tyre which is now a city on the coast of Lebanon. The people of Israel should give equal opportunity under the law and equal treatment under the law to the people of Iran and Iraq and Lebanon because they are blood related family and this is proven by DNA testing. I have a right to speak up on this subject because my DNA test shows the J haplogroup with the J1 subclade which researchers call the Cohanim gene or Cohen gene.
    You can see my DNA test results online at and type in my test kit# FW67ML5Y4D
    I never expected to have this DNA, this J haplogroup with J1 subclade that researchers
    call the “Jewish” gene. There have never been any Jews in my family. It is possible that during the Christian Crusades they may have been threatened with death if they did not convert to Christianity. It is possible that my mother’s mother’s mother’s mother came from a family born before the Jewish religion was created. I am a woman, so my DNA test result is for my mother’s mother’s mother’s mother all the way back to before or during the Bible times.
    Even though there are no Jews in my family, I have a right to speak up on this subject because this is my blood and my brother tested the same for his Y chromosome, J1. So, obviously not all people with the so-called “Cohamin gene” are Jewish. But, blood is blood, and this is my blood, so I have a right because this is my blood to stand up and to say that I don’t want the U.S.A. to give Israel weapons and missles to kill people of my blood in other countries. You all need to calm down and learn to be peaceful. Isn’t it about time?

  • Ms.Ericson
    The Cohen gene is found in Y-Chromosome
    Haplogroup J(J1).However it is this haplogroup designation
    accompanied by distinct STR MARKERS which produces the CMH
    or Cohen gene or markers.A J1 result in itself for the
    Y-Chromosome haplogroup indicates Semitic origins however
    it is not necessarily a confirmation of Israelite or Cohen ancestry.American citizens are not by any means restricted
    to any particular haplogroup and therefore it is your constitutional
    right to lobby for or against funding for the ” Jewish State ”
    based on your status as an American citizen not on the basis of a J1 reading. I am an SNP confirmed Kohen(Kahan)testing positive for
    haplogroup J1 and the Kohen STR Markers. As a true Kohen I am
    closer related to Palestinians and Negev Bedouins than to most
    Israeli Jews and therefore I fully understand your concern.

    (Amir) Ishaq D.Al-Sulaimani;HaKhan Ibn Musa,SNP(M267)J1,CMH

  • If Jewishness, according to current Jewish law, is determined through the mother’s line, then why is DNA testing (YDNA) done through the father’s line in search of the Cohanim or Levy gene? The Y DNA is irrelevant, because the father does not determine Jewishness; the mother does.

    These DNA tests should be done through the maternal line (mtDNA). Case in point: The mother is a Gentile and the father a Jew. The child is considered a Gentile, and not a Jew.

    Ethiopian Jews are making Aliyah through their father’s YDNA, but the father’s line does not determine Jewishness. It makes no sense to test Jews through the father’s line. Jews should be tested through their mother’s line (mtDNA).

    Another case: A female grandchild ultimate offspring of a Jewish grandfather and a Gentile grandmother is considered a Gentile, because her mother’s line is Gentile. Yet, the brother of that female grandchild is tested through the father’s line, (YDNA) for the Cohanim gene, and if that male child has the Cohanim gene, then he is considered a Jew, and a priestly one, at that. So, the sister is Gentile and the brother is Jewish. This makes no sense, and why only the maternal line, mtDNA, should determine Jewishness.

  • well yes this genes is not only jewish gen it is shared with arabic muslim people majority of arabs have j gene alot have j1 gene it is tha abrahimic gene not the jewish gene which also confirmed Torah yet alot ancoster of prophet Muhamed have exact cohanim gene yet as in torah it is the blessed gene as abrahim is blessed ishaq and ishmeal are blessed to no one from arab nor jrws deny the fact that they are cousins

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