This really fucks them up.
you're glowing
If Brin's parents had to leave Russia because of anti-semitism not allowing him to undertake his studies, then surely his grandfather, also Mikhail, who was a professor in Moscow would have been under the same anti-semitism?
He still managed to be a professor of Mathematics
I can find no family further back than this. The whole story is glowing KGB/CIA backdoor via google to me.