Hi SimplySouthern,
I went back to the first page and looked at some of your earlier posts. It clearly shows that you don't have any of the ERAP1 at-risk variants - so all good there.
But, as you pointed out you have 5 of the 7 IL23R at-risk SNPs - not good - so in conjunction with HLA-B27, IL23R must be driving your disease.
As for rs7743761 which you say Promethease locates onto DHFRP2. I think something is wrong there since a quick scan of the internet locates DHFRP2 onto chromosome 19 (I think). But this does not jell with the paper from 2010 that jroc referred to, that suggested rs7743761 is on chromosome 6 on, or near HLA-B27 - it may even be within HLAB27 - and that would lessen its significance.

Dx Oct 2006 B27+ undifferentiated spondlyarthropathy (uSpA) with mild sebhorrhoeic dermatitis and mild Inflammatory Bowel Disease (IBD) controlled by NSD since 2007.