There are paternal and maternal lineage markers in everyone's DNA - not really "genes." The dominant lineage markers of Jews throughout today's world indicate Middle Eastern origin, despite many centuries of dispersion. Kohanim, the Jewish Priestly family, have these markers in the highest percentage because to be a Kohen requires unbroken paternal lineage from Biblical times. But Jewish is not a genetic definition as converts bring other DNA into the community. Spiritually, "Jewish Genes'' are the inborn nature of a Jew to seek God.
World Jewish Congress: Nazi train treasures must go to rightful owners (Reuters)
from the article: 'Jewish gene' theories make waves in Germany, go unnoticed in Israel