HI:
You seem to place a huge amount of emphasis on genetic understanding. While it is important, what has unfolded in the years since the Human Genome Project was first completed, is that we have come to understand for most conditions and diseases, there is no simple mapping from genome to disease. It appears that are often many mutations that may create some small risk of susceptibility, but experience/environment makes a difference as well (the article on Gene–environment interaction is pretty crappy but says some of it) and overall, we really don't understand etiology of many diseases that well at all. Hell we don't even understand what actually kills neurons in AD; we don't understand why all of us have some tau outside of cells at all (its main known functions are intercellular) etc etc... the number of unknowns for AD alone is really stunning.... Jytdog (talk) 19:10, 29 June 2014 (UTC)