User blog comment:Master Sima Yi/Assassinews 02-03-'12 — Leaked AC3 info!/@comment-4374396-20120303024139/@comment-1153722-20120303105200

It's not a family thing, it's not genetical. Altaïr, Ezio and Connor aren't family... :/ it's just a coincidental characteristic Ubisoft puts in to connect the protagonists in yet another way.