If a person's genetic profile can dictate their bone density, their general cognitive ability, their maximum height, their resistance to a selection of distinct pathogens, the composition of their ear wax, their intrinsic personality, their eye color, their hair color, and their skin color, then I don't see why a person's sexuality couldn't possibly be attributed to a measurable integer of alleles as well.  

Everything that makes you [i]you[/i] is locked tightly within your DNA. Your life experiences and the way you were reared have little to do with how you turn out. 

For this reason, it is wholly illogical for anyone to consciously inflict harm, either by proxy or directly, upon gays. There is nothing that they or anyone else can do to alter their "condition". They're born into it; they'll die with it. Straight camps don't work. They, along with anti-gay legislation, should be condemned, dismantled, and ultimately outlawed. 

However, the same consideration must be [cautiously] extended towards homophobes. This will undoubtedly slight the liberal sensibilities of a number of RPG's more progressive denizens, but when put into an evolutionary context, gays and lesbians aren't very conducive to the continued longevity of a tribe (or most animal species for that matter). They aren't likely to engage in sexual intercourse with the converse sex, so it's comparatively improbable that they'll engender a salubrious progeny to help replace those tribal members that have lost their lives to disease, warfare, or natural causes. The collectives that disfavored homosexuality were probably more successful in their procreative endeavors, and therefore helped to solidify homophobia as an inherent facet of the human condition. 

Or maybe people are wary of gays because they go against the status quo. Maybe it's both. Who knows.

Humans never could handle different.