Allotypes *001 and *002 (previously referred by the authors of the earlier paper as 5SNP and WT haplotypes) would be the most common allotypes (*002 more than *001) for healthy controls, remembering of course the tiny sample sizes. The combination *001 and *002 allotype pair would normally not be associated with AS, but clearly you are an exception.
Usually *002, being an efficient trimmer would nullify the effects of *001 which is a 'hypoactive' trimmer.
That's cool, thanks for interpreting that. Good to know that my ERAP1 trimming shouldn't be too wayward. I like how they are looking at the combination of different SNPs and how they affect immunological processes. Seems like that approach would yield much more useful information compared to just looking at the odds ratios for individual SNPs, as it's likely to be a combination of different genes and SNPs that lead to particular pathologies.