If such a thing could be identified.
I kind of doubt that it could. I think with enough applied research, sets of genes that would increase the likelihood of falling into that sin might be found, but we would likely also find those same genes represent a temperament of child that is a greater challenge to raise. A child that is more sensitive and that has greater spiritual capacity than most, and when frustrated he (or she) seeks satisfaction in “idols” which the devil opportunistically presents. Raising the spiritual awareness of society in general will head off a lot of these tragedies (which God can still remedy, although in later life).
Besides scientists inability to find a gay gene, besides that even some scientists (including scientists who also have same-sex attractions) don't think a gay gene will ever be found, we also have to recognize all the other evidence and studies on the subject. And when somebody honestly looks at the evidence it appears obvious nobody is born with an attraction to the same sex.
That's not to take anything away from the very complex subject of same-sex attraction, it's just that everything must be weighed with all the other evidence.