Association of the intergenic single-nucleotide polymorphism rs10865331 (2p15) with ankylosing spondylitis in a Spanish population

Genetic effects of B3GNT2 on ankylosing spondylitis susceptibility and clinical manifestations in Taiwanese

BACKGROUND/PURPOSE

The intergenic SNP rs10865331 at 2p15 was identified as a major risk factor for ankylosing spondylitis (AS) susceptibility in genome-wide association studies (GWAS). B3GNT2 gene regulates polylactosamine synthesis is potentially functionally relevant to AS disease development. We investigated whether SNP rs10865331 and two B3GNT2 SNPs (rs11900673 and rs1136151) are associated with AS susceptibility and disease severity in Taiwanese.

METHODS

Distributions of genotypes, alleles, and haplotypes of three SNPs were compared between 1,472 AS patients and 2,117 healthy blood donors and among AS patients stratified by clinical characteristics.

RESULTS

The intergenic SNP rs10865331 was significantly associated with AS (P_FDR = 1.02E-05) in Taiwanese. In AS patients stratified by positivity of HLA-B27 and syndesmophyte formation, all three B3GNT2 locus SNPs (rs11900673, rs1136151, and rs10865331) were significantly associated with syndesmophyte formation among HLA-B27 positive AS patients. Haplotype analyses revealed that the "CTA" (rs11900673C/rs1136151T/rs10865331A) haplotype was significantly associated with AS susceptibility (Padj = 0.0177) and syndesmophyte formation (Padj = 0.016) in HLA-B27 positive patients. In contrast, "TCG" (rs11900673T/rs1136151C/rs10865331G) haplotype showed protection against AS development (Padj = 0.0005 for HLA-B27 positive and Padj = 0.004 for HLA-B27 negative, respectively) and syndesmophyte formation (Padj = 0.0017) in HLA-B27 positive patients. Furthermore, B3GNT2 mRNA expressions were negatively associated with erythrocyte sedimentation rate (ESR, P = 0.0103), C-reactive protein (CRP, P = 0.0353), Bath ankylosing spondylitis functional index (BASFI, P = 0.0171), and syndesmophyte formation (P = 0.0148).

CONCLUSION

Our data suggest that B3GNT2 gene may contribute to AS development and affect AS severity by interacting with HLA-B27 in Taiwanese.

Pathogenic variants screening in seventeen candidate genes on 2p15 for association with ankylosing spondylitis in a Han Chinese population

OBJECTIVES

Previous studies have found the association between rs10865331 in 2p15 area and ankylosing spondylitis (AS). This study aimed to identify additional functional genetic variants in 2p15 region associated with AS susceptibility.

METHODS

We used next generation sequencing (NGS) in 100 AS cases and 100 healthy controls to screen AS susceptible genetic variants, and validated these variants in 620 cases and 620 controls by using imLDRTM technique for single nucleotide polymorphism (SNP) genotyping.

RESULTS

Totally, we identified 12 SNPs that might confer susceptibility to AS. Of those SNPs, three (rs14170, rs2123111 and rs1729674) were nominally associated (P<0.05) with AS, but were no longer statistically significant after Bonferroni correction. After stratified by gender, another two SNPs (rs11428092 and rs10208769 in USP34) were associated with AS in males but not females, though this was not statistically significant after Bonferroni correction. In addition, rs1729674, rs14170, rs2123111 and rs10208769 were in strong linkage disequilibrium (LD) and were further enrolled in haplotype analysis. A novel haplotype TAGA was found to be associated with a decreased risk of AS (odds ratio (OR) (95% confidence interval (CI)) = 0.832 (0.705-0.982)). Beyond that, we also demonstrated a strong relationship between rs10865331 and AS susceptibility (OR (95% CI) = 1.303(1.111-1.526)).

CONCLUSIONS

rs14170 and rs2123111 inUSP34 and rs1729674 in C2orf74 may be associated with AS susceptibility in Han Chinese population. USP34 and C2orf74 in 2p15 region may be AS novel susceptibility genes.

Association Study of Single Nucleotide Polymorphisms Rs4552569/Rs17095830 with Ankylosing Spondylitis in A Chinese Population

Genetics play a key role in ankylosing spondylitis (AS). A previous genome-wide association study (GWAS) showed that rs4552569 (on 5q14.3) and rs17095830 (on 12q12) were associated with the risk of AS in Han Chinese, which was not replicated in other two studies. In the current study, rs4552569 and rs17095830 were genotyped in 735 Han Chinese AS patients and 1204 healthy controls using high resolution melting analysis (HRMA). We compared the distributions of genotypes and alleles between AS cases and healthy controls. Rs30187 and rs10865331, which were reported to be associated with AS susceptibility in various populations, were also genotyped and analyzed as positive controls. The results showed that no association between rs4552569/rs17095830 polymorphisms and AS susceptibility was found. On the other hand, an association between rs17095830 and one of AS complication (inflammatory bowel disease) was observed (allelic P value=0.0180; odds ratio[OR]=1.739; 95% confidence interval [CI]=1.146-2.639).

rs10865331 associated with susceptibility and disease severity of ankylosing spondylitis in a Taiwanese population

Ankylosing spondylitis (AS) is a highly familial rheumatic disorder and is considered as a chronic inflammatory disease. Genetic factors are involved in the pathogenesis of AS. To identify genes which render people susceptible to AS in a Taiwanese population, we selected six single-nucleotide polymorphisms (SNPs) from previous genome-wide association studies (GWASs) which were associated with AS in European descendants and Han Chinese. To assess whether the six SNPs contributed to AS susceptibility and severity in Taiwanese population, 475 AS patients fulfilling the modified New York Criteria and 527 healthy subjects were recruited. We found that rs10865331 was significantly associated with AS susceptibility and with Bath AS Function Index (BASFI). The AA and AG genotypes of rs10865331 were also significantly associated with a higher erythrocyte sedimentation rate. Our findings provided evidence that rs10865331 is associated AS susceptibility and with disease activity (BASFI) in a Taiwanese population.

Association of FCRL4 polymorphisms on disease susceptibility and severity of ankylosing spondylitis in Chinese Han population

Previous studies have found that the Fc receptor-like (FCRL) molecule, involved in controlling B cell signaling, may contribute to the autoimmune disease process. Many studies have reported the relation of FCRL gene family with SLE and RA. We hypothesized that FCRL4 may be a key gene for ankylosing spondylitis (AS) development. To test this hypothesis, we screened FCRL4 polymorphisms in the Chinese Han population. Five tag single nucleotide polymorphisms (SNPs), including rs14335, rs849826, rs10489674, rs2778003, and rs2777963, were selected. Using a case-control study, five tag SNPs, which captured the majority of known common variation within FCRL4 gene, were selected and genotyped by Multiplex Snapshot technique. We analyzed 299 patients and 300 controls from China. The genotype analysis demonstrated that one of the FCRL4 tag SNPs rs2777963 TT genotype may be a risk factor of AS (χ(2) = 7.374, p = 0.024). The haplotype analysis indicated that there were no significant differences between AS cases and controls. Patients with AS who had rs14335 AA genotype had a significantly declined visual analogue scale patient's global assessment scores compared to those with the GG genotype (31.21 ± 26.25 vs 40.54 ± 25.40, p = 0.035) and GA genotype (38.29 ± 24.94 vs 40.54 ± 25.40, p = 0.044), and in locus rs10489674, TT genotype had significantly increased Bath Ankylosing Spondylitis Disease Activity Index scores compared to those with the CC genotype (4.73 ± 2.43 vs 3.15 ± 1.61, p = 0.003) and CT genotype (4.73 ± 2.43 vs 2.97 ± 1.71, p = 0.001). The FCRL4 polymorphisms may play an important role in the susceptibility and severity of AS in the Chinese Han population.

Genetic polymorphisms inside and outside the MHC improve prediction of AS radiographic severity in addition to clinical variables

OBJECTIVE

The aim of this study was to analyse if single nucleotide polymorphisms (SNPs) inside and outside the MHC region might improve the prediction of radiographic severity in AS.

METHODS

A cross-sectional multi-centre study was performed including 473 Spanish AS patients previously diagnosed with AS following the Modified New York Criteria and with at least 10 years of follow-up from the first symptoms of AS. Clinical variables and 384 SNPs were analysed to predict radiographic severity [BASRI-total (BASRI-t) corrected for the duration of AS since first symptoms] using multivariate forward logistic regression. Predictive power was measured by the area under the receiver operating characteristic curve (AUC), specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

The model with the best fit measured radiographic severity as the BASRI-t 60th percentile and combined eight variables: male gender, older age at disease onset and six SNPs at ADRB1 (rs1801253), NELL1 (rs8176785) and MHC (rs1634747, rs9270986, rs7451962 and rs241453) genes. The model predictive power was defined by AUC = 0.76 (95% CI 0.71, 0.80), being significantly better than the model with only clinical variables, AUC = 0.68 (95% CI 0.63, 0.73), P = 0.0004. Internal split-sample analysis proved the validation of the model. Patient genotype for SNPs outside the MHC region, inside the MHC region and clinical variables account for 26, 38 and 36%, respectively, of the explained variability on radiographic severity prediction.

CONCLUSION

Prediction of radiographic severity in AS based on clinical variables can be significantly improved by including SNPs both inside and outside the MHC region.

Association of ORAI1 haplotypes with the risk of HLA-B27 positive ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammation of the sacroiliac joints, spine and peripheral joints. The aetiology of ankylosing spondylitis is still unclear. Previous studies have indicated that genetics factors such as human leukocyte antigen HLA-B27 associates to AS susceptibility. We carried out a case-control study to determine whether the genetic polymorphisms of ORAI1 gene, a major component of store-operated calcium channels that involved the regulation of immune system, is a susceptibility factor to AS in a Taiwanese population. We enrolled 361 AS patients fulfilled the modified New York criteria and 379 controls from community. Five tagging single nucleotides polymorphisms (tSNPs) at ORAI1 were selected from the data of Han Chinese population in HapMap project. Clinical statuses of AS were assessed by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Bath Ankylosing Spondylitis Global Index (BAS-G). Our results indicated that subjects carrying the minor allele homozygote (CC) of the promoter SNP rs12313273 or TT homozygote of the SNP rs7135617 had an increased risk of HLA-B27 positive AS. The minor allele C of 3′UTR SNP rs712853 exerted a protective effect to HLA-B27 positive AS. Furthermore, the rs12313273/rs7135617 pairwise allele analysis found that C-G (OR 1.69, 95% CI 1.27, 2.25; p = 0.0003) and T-T (OR 1.75, 95% CI 1.36, 2.27; p<0.0001) haplotypes had a significantly association with the risk of HLA-B27-positive AS in comparison with the T-G carriers. This is the first study that indicate haplotypes of ORAI1 (rs12313273 and rs7135617) are associated with the risk of HLA-B27 positive AS.