I think everyone with a relative with the Pitt name must have been told they're related at some point. (I know I've been told that)
There's no suggestion of any descendants for Pitt the younger. But if you're descended from his great, great, great, great, grand father you're still related to the famous two.
I currently have four places where my tree links to famous surnames where no clear link to the significant members can be found, yet family history tells of a link...