How many genes outside of the MHC locus have been genetically associated to Rheumatoid Arthritis through GWAS?
['Genome-Wide Association Studies (GWAS) have allowed the characterization of more than 40 new susceptibility genes and the confirmation of a marked differential genetic background between patients expressing anti-cyclic citrullinated peptide antibodies (ACPA, approximately 80% of all RA patients) and ACPA negative RA patients', 'Firstly, we review here the major advances in identifying RA genetic susceptibility markers both within and outside of the MHC. ', 'The most relevant non-HLA gene single nucleotide polymorphisms (SNPs) associated with RA include PTPN22, IL23R, TRAF1, CTLA4, IRF5, STAT4, CCR6, PADI4. Large genome-wide association studies (GWAS) have identified more than 30 loci involved in RA pathogenesis.', 'The meta-analysis results showed that: (1) 30, 28 and 26 SNPs were significantly associated with RA (P<0.01) for the allele, dominant, and recessive models, respectively.', 'This paper compares corresponding non-MHC genomic regions identified in rodent and human genome-wide association studies (GWAS). To date, over 30 non-MHC RA-associated loci have been identified in humans, and over 100 arthritis-associated loci have been identified in rodent models of RA', 'Interestingly, a series of candidate genes have been identified outside of the classical major histocompatibility (MHC) locus, which had long been regarded as the major contributor to the pathogenesis of this disease', 'Among these genes, PTPN22 plays an outstanding role. CD40, STAT4, PRM1, and TNFAIP3 also seem to be of relevance', 'Genome-wide association studies (GWASs) added about 10 new loci to the list of already more than 20 loci associated with RA, so the list is now over 30', 'Previous studies demonstrate that 6 of the established non-HLA CD and RA risk loci (out of 26 loci for each disease) are shared between both diseases.', 'These new associations bring the total number of confirmed rheumatoid arthritis risk loci to 31 among individuals of European ancestry', 'An additional 11 SNPs replicated at P < 0.05, many of which are validated autoimmune risk alleles, suggesting that most represent genuine rheumatoid arthritis risk alleles.', 'Genome-wide association studies have expanded the number of validated RA risk loci beyond HLA-DRB1 "shared epitope" alleles to include additional major histocompatibility complex (MHC) risk alleles and more than 10 regions outside the MHC.', 'We successfully identified 41 significant SNPs relevant to RA, 25 associated genes and a number of important SNP-SNP interactions (SNP patterns)', 'A total of 47 candidate regions were identified. ']
['Large genome-wide association studies (GWAS) have identified more than 30 loci involved in RA pathogenesis. To date, over 30 non-MHC RA-associated loci have been identified in humans, and over 100 arthritis-associated loci have been identified in rodent models of RA. The most relevant non-HLA gene single nucleotide polymorphisms (SNPs) associated with RA include PTPN22, IL23R, TRAF1, CTLA4, IRF5, STAT4, CCR6, PADI4. Previous studies demonstrate that 6 of the established non-HLA CD and RA risk loci (out of 26 loci for each disease) are shared between both diseases.']
['more than 30']