Hi there Peter! Welcome ! The gene HLA B27 is the gene that most folks with AS have. Some of us don't have it, but now I've been informed that sometimes we do have a B27 gene that has been overlooked (see John the Dragon Slayer's post). This is of much interest to me becasue I really wanted to know just how I developed this disease. Stuff like, am I gonna pass it on to my kids or is there something that I should never let the be exposed to are constantly going thru my brain. I guess it's worth getting the gene test if you are curious about how you got AS. To my knowledge, how you got AS does not impact the course of treatment. Hope to see ya around here chatting soon, take care, JP