Apologies for contributing to this going even further afield of the bounds of HN-ish discussion, but I can't help but point out the relevance of one of the big points from the Council of Trent. The Church argued in favor of the idea that original sin is passed on through "propagation, not imitation." [1] That is, original sin is passed on from generation to generation rather like a disease, instead of from children simply imitating their parents.
But although this "disease model" of sin can sometimes be a useful theological model, as you say, it is most emphatically not a genetic disturbance or a true disease in the medical sense of the word.
But although this "disease model" of sin can sometimes be a useful theological model, as you say, it is most emphatically not a genetic disturbance or a true disease in the medical sense of the word.
[1] http://www.vatican.va/archive/ccc_css/archive/catechism/p1s2...