Yeah, I am not a language expert, but from what I remember, the unique way that some letters/sounds are pronounced is the same and the grammer/sentence structure the same. I can't remember if it was Welsh or Gaelic, though.

Yiu can also trace the frequency of Rh- blood in Irish people and Jewish.

It could have been that the modern Jews deliberately married into Rh- as most Preaidents and royals have been Rh- (a rare, recessive blood type).