Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.
French investigators have identified in 70 families a second allele predisposing to a group of inflammatory rhematic diseases—the spondyloarthropathies (SpA). MHC HLA-B27 is associated with all familial SpA—ankylosing spondylitis; reactive arthritis; a subspecies of psoriatic arthritis; arthritis with inflammatory bowel disease; and undifferentiated spondyloarthropathy—but now HLA-DR4 has also been shown to be significantly associated, independently of linkage disequilibrium with HLA-B27.
The investigators found that the gene frequencies of HLA-A, B, C in the HLA-B27 haplotypes in these families were similar to those in a random sample of the French population; the same was true for HLA-DR except for DR 13, which was overrepresented. Transmission disequilibrium tests for HLA-DR alleles performed on all haplotypes showed excess transmission of HLA-DR4 to family members affected with SpA (52 positive v 20 negative; 169 tested) and reduced transmission in unaffected siblings with HLA-B27 (10 positive v 18 negative; 71 tested). Repeating the test with HLA-B27 negative haplotypes showed excess transmission of HLA-DR4 to family members with SpA (20 positive v 6 negative; 156 tested) but the reverse for unaffected siblings with HLA-B27 (2 positive v 8 negative; 70 tested), confirming HLA-DR4 was not in linkage disequilibrium with HLA-B27.
The study population included 188 patients and first degree relatives from 70 families with at least two affected members and 198 HLA-B27 negative haplotypes randomly selected from the French population.