Jews do not have a "levitical genetic marker". Saying ignorant things to fabricate a race is ignorant racism.
"Beta Israel" are blacks, by race. Jews by religion. For information on their genetics:
https://en.wikipedia.org/wiki/Beta_Israel#Genetics The word "levitical" doesn't appear anywhere in that section on genetics.
The black Jews were hardly welcomed into Israel, because most Jews think blacks subhuman. They were hesitantly allowed in, by the same criteria as other Jews. But, Israel has no genetic criteria for admission. To be allowed to immigrate to Israel, you are required to be anti-Christian, in Talmudic tradition, along with your spouse and parents. Again, there is no genetic criteria (and, no such thing as Christian Jews).