There's definitely an association with transsexuality, statistically. And anecdotally I've noticed proportionally more bi, gay, and lesbian people who are autistic. I'm a borderline-lesbian myself, and trans-adjacent since I was born intersex and don't fully feel comfortable with the gender binary.
I'd guess the most likely explanation is that we're less encumbered by social norms, so we're more willing to admit things that might otherwise be taboo or embarrassing about ourselves. If true, that'd mean there are roughly as many neurotypical people with LGBT leanings, but they have more desire to bury it.
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Don't believe the gender tag. I was born intersex and identify as queer, girl-leaning. So while I can sometimes present as an effeminate guy, that's less than half the time and if anything I'd prefer it say "female" of the two choices offered. I can't change it though, it's bugged.