Despite this, efforts to delineate host genetic susceptibility have so far been limited to a number of small candidate gene studiesmany focused on the HLA locusthe results of which have been inconsistent and largely inconclusive8. Here we report a genome-wide association study (GWAS) of RHD susceptibility in the endemic settings of Oceania, where the disease remains a leading cause of premature death and disability9. failure and stroke among young and middle-aged adults in developing countries1. Although reliable data remain scarce, it is likely the disease affects at least 16 million individuals worldwide, causing an estimated 300,000 premature Picropodophyllin deaths each year2; however, relative to its global impact, RHD has been largely neglected by researchers and funders alike3. Consequently, there has been limited progress towards understanding pathogenesis that has hampered efforts in disease control and development of novel therapies and an effective vaccine4. Host genetic susceptibility is one compelling feature of the disease that awaits rigorous investigation. For over a century, clinicians have noted the strong familial propensity of acute rheumatic fever (ARF)5, and it was recently estimated on the basis of twin studies dating back to the 1930s that monozygotic twins have sixfold Picropodophyllin greater concordance than dizygotic twins6. Moreover, even in highly endemic settings where childhood GAS infections are ubiquitous, only a minority of the population develop ARF or RHD during their lifetime (up to 5C6%), and this may indicate that the disease develops only in those who are genetically predisposed7. Despite this, efforts to delineate host genetic susceptibility have so far been limited to a number of small candidate gene Picropodophyllin studiesmany focused on the HLA locusthe results of which have been inconsistent and largely inconclusive8. Here we report a genome-wide association study (GWAS) of RHD susceptibility in the endemic settings of Oceania, where the disease remains a leading cause of premature death and disability9. We identify a novel susceptibility signal in the immunoglobulin heavy chain (IGH) locus centring on a haplotype of nonsynonymous variants in the gene segment corresponding to the gene segment (rs11846409, FE meta-analysis, (Supplementary Fig. 7c), all part of the previously defined value from an inverse-variance weighted fixed-effects meta-analysis is plotted against genomic position. The blue horizontal line indicates suggestive significance (FE meta-analysis, locus with RHD susceptibility.(a) For each variant in the 99% credible set, the common logarithm of the Bayes’ factor is plotted against genomic position. Variants are coloured by linkage disequilibrium with the most associated variant averaged across the entire data set (estimated and locations of expressed IGH gene segments are indicated by blue rectangles below the axis. (b) Forest plot for the heavy variable domain (Protein Databank 4FQQ) showing both heavy (blue) and light (white) chains with both the first (CDR-H1, green) and second (CDR-H2, Picropodophyllin violet) heavy chain complementarity determining loops and the heavy chain interface framework loop (HIFL, red) highlighted. The positions that distinguish in a subset of the samples (Supplementary Fig. 8). Among the 339 sequenced individuals included in the association analyses we identified three common haplotypes (Supplementary Fig. 9), two known, matching the to that of locus rather than the locus because the sequence surrounding test, locus (250?kb, FE meta-analysis, minimum allele that we speculate has arisen through a gene conversion event. Given the highly repetitive nature of the locus, it is plausible this is one of many such events, underscoring the need for further mapping of the locus to facilitate more accurate disease association studies. Moreover, particular effort will be needed to understand the diversity of IGH polymorphism in non-European populations30, not least because these groups experience a disproportionate burden of infectious and inflammatory disease. Overall, however, our link between an allele and RHD susceptibility may be Picropodophyllin an important step forward for understanding the immunogenetic determinants of autoimmune disease in general. It has long been established that immunoglobulin deposits are an important feature of the pathology of RHD31. Interestingly, human hybridoma-derived immunoglobulins containing related heavy chain domains were previously shown to bind relevant streptococcal and host antigens Rabbit Polyclonal to CDH24 including group A streptococcal carbohydrate and cardiac myosin32. In addition, autoantibodies against the same heavy chain domains were among 12 autoantigens identified in sera from ARF patients screened using a human heart complementary DNA library33. At present, we conjecture that individuals who possess the (ref. 47) and genes48. Most samples were obtained from healthy adult volunteers but series of cord bloods.
