"Roughly 1 in 4 lisbian or gay teens and 15 percent of bisixual teens are homeless, versus 3 percent of exclusively heterosixual teens, finds a Children's Hospital Boston study of more than 6,300 Massachusetts public high school students. Moreover, among teens who were homeless, those who were gay, lisbian or bisixual (GLB) were consistently more likely than heterosixuals to be on their own, unaccompanied by a parent or guardian."
http://www.childrenshospital.org/newsroom/Site1339/mainpageS1339P751.html
I don't normally post in community discussion, but this was pretty shocking when I read it. Other studies seem to say the same thing, so it's not a one-off result.