I think this relates to intersex persons, not LGBTQ persons per se. Intersex persons, in their anatomical makeup, i.e. their genetic makeup, are literally gender ambiguous. They literally possess either chromosomal anomalies like the ones you mention, or they have reproductive organs of both male and female anatomies.
I think we need to distinguish between LGBTQ and Intersex, although they could overlap. But, you could (and usually do) have homosexual males or a lesbian females or bi-sexual males or a transgender females whose biology clearly places them in one distinctive anatomical category of either male or female. But, their decision is to ignore their biological make-up and through an act of the will choose to be or act as a member of the other anatomical class. They act against the clearly perceived and empirically verifiable nature of their own bodies.
Moreover, we would probably need to make a distinction between biological men or women who are same-sex attracted, yet still consider themselves men and women, and biological men and women who may or may not be same-sex attracted, yet want to be or act as if they were a non-male or a non-female.
The intersex person, however, struggles to know biologically whether they fit into the anatomical category “male” or “female” because their biology is simply unclear. It is a difficult issue, but I think in these, very few cases (i.e. the case of the intersexed person), one should be allowed the freedom to choose which anatomical category (male or female) they do feel more comfortable in, and live as such.
There is a thoughtful book on the issue of Intersex by Megan de Franza, and while I strongly disagree much of her methodology and with many of her conclusions, I can still say it is well researched and does bring to light some of the issues surrounding intersex persons (formerly known as “Hermaphrodites”). So, in that sense I do recommend it while also rejecting its conclusions:
Further, regarding the idea that homosexual or same-sex attraction can be grounded chromosomally, I think there is no good evidence for this; although I am basing this mainly on a well-known and well-regarded analysis by Dr. Paul McHugh, found here:
That said, however, even if there is no “gay gene” to speak of, or even if our genes are largely irrelevant when it comes to our sexual desires, I think we should take into account as Christians that if sexual attraction towards the same biological sex is just psychological, that psychological dispositions are still very, very strong and binding things. Most of us struggle with psychological problems that facilitate some kind of sin. Also, these, on my view, can be generational strongholds that effect not only individuals but families.
Finally, I would say this though. Even if it was proven that sexual attraction of some sort where grounded in chromosomal realities, this would not do much to overturn the biblical view of human sexuality, since we already know from Scripture that all human persons are corrupt and fallen from birth. None of us is without sin, nor without some proclivity to sin, and that even from our earliest moments. So, we all need to be redeemed from something: homosexual desire, anger, depression, lust, etc.
Hope this helps; thanks for the very good, yet very challenging question.