I was just giving the movie poetic license to say "infected by your genetics" because it does work better in a song than "I inherited your genetics" and still gets the point across. The idea in the article above is really interesting, that having certain alleles of certain genes can make you more susceptible to an infection, but in the movie I think it was that she had a straightforward genetic disorder, and hence not technically "infected" by some pathogen.

Still interesting to thing about, its a great article!!