As a part of the programming in the Inspiration Station it's unknown if he's meant to have any family.
|“|| Mortimer: I've got 3,456,270,496 rows of books, all alphabetized and numerically ordered to take care of.
|“|| Matthew Parker: I know, I know: don’t tinker around with other people’s stuff if you don’t have permission first.
Mortimer: Exactly, my boy. You’ve got perspict...er...perspir...perspaper...uh, you’re very smart.