The study strengthens other research suggesting Jewish people from Europe and the Middle East share more DNA with one another than they do with outside groups, study author Harry Ostrer, a medical geneticist at the Albert Einstein College of Medicine in New York, said.
"Jews tend to be more related to one another than they are to non-Jews, including non-Jews living nearby -- it's true in every region," he told the Los Angeles Times.
DNA carries a record of Jewish migrations over the centuries, the study researchers said.
Some DNA traces back to the Middle Eastern peoples thought to have migrated to North Africa more than 2,000 years ago, while other DNA proves connections to Spanish and Portuguese Jews who fled to North Africa after their expulsion from the Iberian Peninsula in the late 15th century.
Ostrer and his colleagues analyzed DNA samples from 145 people of North African Jewish origin from Morocco, Algeria,Tunisia, Djerba (an island off the Tunisian coast) and Libya.
North African Jewish populations clearly had genetic patterns more similar to European and Middle Eastern Jews than non-Jewish people currently living in the region, the researchers said, suggesting that once established in their communities Jews in the region did not often intermarry with non-Jewish neighbors.