For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
Kelly Yochum
What mankind inherited was not sin of itself. If it was, there would be no babies, autistic, or young children in Heaven.
What we inherited was the "knowledge of good and evil", and thus, as soon as someone develops to the age or mental capacity to know what sin is, that person needs Christ as Saviour in their personal life.