How is this different?  That's an easy one: it isn't a 'terrible disease or disability' to be a person who is transgendered; your comparison to diabetes is absolutely off the mark.
According to Trump & the Trumpanzees, trans people's medical issues cost about 8.5 million per year to the U.S. military and as we should all know by now, that's about one-fifth of what's spent on Viagra, and less than half of what Trump has spent on trips to Mar-El-Largo and his other properties.