User blog comment:Xilinoc/Ch. 565 (Mangapanda is run by lazy barnacles)/@comment-1268838-20140122195654/@comment-26420452-20140123065529

KawaTsuyo, here's how I gather it: the people who touched baby Yhwach had a really short life expectancy but some of them managed to have families. The children inherited Yhwach's piece of soul, but not the shortened life and that's how Quincy families were created.