As previously discussed, close to 20% of the Cochin “Black Jews” are Rh negatives.
Today, only 15 of them live in India with 7,000-8,000 in Israel.
Their presence in India, however, may have gone back thousands of years back to the time of King Solomon.
See https://en.wikipedia.org/wiki/Mountain_Jews for references on Y-DNA studies on the Mountain Jews and their history. If there is a high proportion of Rh Neg among certain Jewish groups, I would be interested to see how that connects to the Y-DNA and MtDNA. So far genetic genealogy and medical genealogy seem to be mostly separate.