rs7775228 is one of three HLA region SNPs used to tag the DQ2.2 haplotype in gs221. [PMID 18509540]
rs7775228(T) was found to be associated with increased risk for osteoarthritis among Japanese, but not Europeans, with an odds ratio of 1.34 (CI: 1.21-1.49, combined p = 2.43×10e?8). This SNP is also in linkage disequilibrium with rs10947262, which was found to be associated in multiple populations with osteoarthritis.[PMID 20305777]
23andMe reports that the C allele at rs7775228 is associated with hay fever (allergic rhinitis and allergy to grass pollen. [PMID 22036096]
[PMID 19950296] Contribution of a haplotype in the HLA region to anti-cyclic citrullinated peptide antibody positivity in rheumatoid arthritis, independently of HLA-DRB1
||Genome-wide association study identifies three new susceptibility loci for adult asthma in the Japanese population.
[PMID 19458352] Primary biliary cirrhosis associated with HLA, IL12A, and IL12RB2 variants.