IL7RA polymorphisms and susceptibility to multiple sclerosis

Soluble IL-7Rα/sCD127 in Health, Disease, and Its Potential Role as a Therapeutic Agent

Soluble cytokine receptors can influence immune responses by modulating the biological functions of their respective ligands. These effects can be either agonistic or antagonistic and a number of soluble cytokine receptors have been shown to play critical roles in both maintenance of health and disease pathogenesis. Soluble IL-7Ra (sCD127) is one such example. With its impact on the IL-7/CD127 pathway, which is fundamental for the development and homeostasis of T cells, the role of sCD127 in health and disease has been extensively studied in recent years. Within this review, the role of sCD127 in maintaining host immune function is presented. Next, by addressing genetic factors affecting sCD127 expression and the associated levels of sCD127 production, the roles of sCD127 in autoimmune disease, infections and cancer are described. Finally, advances in the field of soluble cytokine therapy and the potential for sCD127 as a biomarker and therapeutic agent are discussed.

Dysregulation of microRNAs regulating survivin in CD4+ T cells in multiple sclerosis

BACKGROUND

Impaired elimination mechanisms of the autoreactive lymphocytes, like T lymphocytes, via apoptosis may be the cause of continues inflammatory state in multiple sclerosis (MS). BIRC5 gene codify for the survivin, which participates in the modulation of apoptosis and cell survival. The objective of this study was investigation of the role of important confirmed miRNAs, including miR-335, miR-485, miR-542, and miR-708, in the regulation of survivin mRNA in the CD4+ T cells of MS cases.

METHODS

In this study, 50 RRMS patients as well as 50 healthy matched controls were recruited. The peripheral blood mononuclear cells (PBMCs) were isolated from whole blood samples and CD4+ T cells were prepared. After that, RNA was extracted, cDNA was synthesized, and the expression levels of miR-335, miR-485, miR-542, and miR-708 were measured using Real-time PCR. Moreover, the mRNA expression of survivin was detected. Serum level of survivin was detected using ELISA.

RESULTS

The mRNA of survivin was 2-folds upregulated in the CD4+ T cells from MS patients in comparison to the healthy controls (P = 0.0053). Serum level of survivin was higher in patients than controls. There was statistically significant downregulation of miR-485 (P = 0.001) and miR-708 (P = 0.011) in CD4+ T cells of patients compared with controls. The miR-485 downregulation had statistically significant correlation with the mRNA expression and serum level of survivin.

CONCLUSION

miRNAs play a role in the regulation of survivin, and therefore apoptosis of CD4+ T cells, and hence are probably participating in a persistent inflammatory condition in MS patients.

Assessment of IL-7RA T244I Polymorphism as a Risk Factor of Multiple Sclerosis in Turkish Population

Introduction

The T244I variant of the IL-7RA gene, rs6897932, is one of the first polymorphisms found to be associated with the development of multiple sclerosis (MS). Although several studies provided evidence for the association of MS and this variant, other studies could not confirm this result. These inconsistent results suggest that the role of this polymorphism in the development of disease is associated with ethnicity.

Methods

We investigated rs6897932 polymorphisms in a large cohort of patients with MS and healthy controls in a turkish population.

Results

In our study, there were no significant differences in genotype frequencies in the IL-7RA rs6897932 polymorphism and no significant difference between C and T alleles in patients with MS and controls.

Conclusion

This study is the first to evaluate the risk of the rs6897932 polymorphism in turkish patients with MS.

Variants in the IL7RA gene confer susceptibility to multiple sclerosis in Caucasians: evidence based on 9734 cases and 10436 controls

Recently, numerous genome wide association studies (GWAS) and other case-control association studies examining the relationship between interleukin-7 receptor α chain (IL7RA) gene rs3194051, rs987107, rs11567686, and rs11567685 variants and multiple sclerosis (MS) risk have been conducted, but the conclusions have been inconsistent. The main objective of this meta-analysis was to more precisely explore the association of these four IL7RA variants with MS development. Twenty-seven eligible studies involving 9734 cases and 10436 controls were included in the present meta-analysis. Power calculation, publication bias, sensitivity analysis and cumulative meta-analysis were performed to derive a reliable conclusion. Our study indicated three IL7RA loci were significantly associated with increasing MS risk (rs3194051: recessive model: OR = 1.22, 95% CI 1.08–1.38; rs987107: recessive model: OR = 1.44, 95% CI 1.22–1.69; and rs11567686: dominant model: OR = 1.18, 95% CI 1.01–1.37). Additionally, IL7RA rs11567685 variants might not be related to MS development. In all, IL7RA locus polymorphisms could play an important role in the predisposition to MS, which could contribute to a better understanding the pathogenesis of multiple sclerosis.

Interleukin 7 receptor polymorphisms and the risk of multiple sclerosis: A meta-analysis

BACKGROUND

Multiple sclerosis (MS) is considered as the most common chronic inflammatory neurologic disorder diagnosed in young adults. Both environmental and genetic factors may influence risk of MS development. Interleukin 7 receptor (IL7R) is one of the most studied gene polymorphism on MS that may play a possible role in MS development. The most studied polymorphism of IL7R gene is "rs6897932" polymorphism on IL7Rα gene (IL7RA).

METHODS

PubMed, Scopus, and Google scholar databases were searched for all of related studies on the association of IL7RA polymorphism with single nucleotide polymorphism (SNP) ID of "rs6897932" and the risk of MS through August 07, 2015. After exclusion of irrelevant articles, 11 eligible studies were selected, which were analyzed to determine an association between the MS and IL7R T244I polymorphism (rs6897932). For identification of this association, odds ratios (ORs) and 95% confidence interval (95% CI) were calculated. Four models of allelic (T vs. C), co-dominant genotype (TT vs. CC), dominant (TT+CT vs. CC), and recessive genotypes (TT vs. CT+CC) were considered to check the possible role of rs6897932 polymorphism in MS. A sensitivity analysis was conducted to find the reliability of this study. Furthermore, funnel plots were used to evaluate publication bias.

RESULTS

A total of 11 case-control studies were identified through this meta-analysis, which containing 6752 cases and 7349 controls. In overall, the frequency of the C allele was found to be higher in patients with MS compared to healthy controls (75.66% vs. 72.19%). T allele was significantly associated with the decreased risk of MS in a random effect model (T vs. C: OR=0.84, 95% CI=0.77-0.92, P-value <0.001). In the co-dominant, dominant, and recessive genotypes models, a significant association between the IL7R T244I polymorphism and MS risk was demonstrated (TT vs. CC: OR=0.70, 95% CI=0.61-0.80, P-value <0.001; TT+CT vs. CC: OR=0.82, 95% CI=0.73-0.92, P-value <0.001; TT vs. CT+CC: OR=0.76, 95% CI=0.66-0.87, P-value <0.001). Sensitivity analysis revealed that this study is reliable. There was no evidence of publication bias.

CONCLUSION

It was demonstrated that the IL7R T244I polymorphism was associated with susceptibility to MS. However, more well-designed studies with large sample size are needed to validate this association between this single nucleotide polymorphism and MS.

GWAS-identified multiple sclerosis risk loci involved in immune response: validation in Russians

Multiple sclerosis (MS) is a chronic neuro-inflammatory disease of complex etiology. The results of GWAS, a high-throughput method to discover genetic architecture of MS, require replication in independent ethnic groups. We performed a replication study of nine GWAS-identified SNPs in immune response in Russians. Associations of CLEC16A and IL2RA with MS were validated. Besides, we observed the associations of CLEC16A and IRF8 in women, and IL7RA and CD58 in men. With multi-locus association analysis two protective biallelic combinations: (TNFRSF1A*T+CLEC16A*A) and (TNFRSF1A*T+IRF8*A) were identified in women. Associations of CLEC16A*G/G and both biallelic combinations in women with MS survived the permutation test.

Genetic variants in IL2RA and IL7R affect multiple sclerosis disease risk and progression

Multiple sclerosis (MS) is a common demyelinating neurodegenerative disease with a strong genetic component. Previous studies have associated genetic variants in IL2RA and IL7R in the pathophysiology of the disease. In this study, we describe the association between IL2RA (rs2104286) and IL7R (rs6897932) in the Canadian population. Genotyping 1,978 MS patients and 830 controls failed to identify any significant association between these variants and disease risk. However, stratified analysis for family history of disease and disease course identified a trend towards association for IL2RA in patients without a family history (p = 0.05; odds ratio = 0.77) and a significant association between IL7R and patients who developed progressive MS (PrMS) (p = 0.002; odds ratio = 0.73). Although not statistically significant, the effect of IL2RA (rs2104286) in patients without a family history of MS indicates that the genetic components for familial and sporadic disease are perhaps distinct. This data suggests that the onset of sporadic disease is likely determined by a large number of variants of small effect, whereas MS in patients with a family history of disease is caused by a few deleterious variants. In addition, the significant association between PrMS and rs6897932 indicates that IL7R may not be disease-causing but a determinant of disease course. Further characterization of the effect of IL2RA and IL7R genetic variants in defined MS subtypes is warranted to evaluate the effect of these genes on specific clinical outcomes and to further elucidate the mechanisms of disease onset and progression.

The influence of non-HLA gene polymorphisms and interactions on disease risk in a Western Australian multiple sclerosis cohort

Non-Human Leukocyte Antigen (HLA) genes have concomitant, although modest, effects on multiple sclerosis (MS) susceptibility; however findings have varied in different populations. Here we present the results of an association study of 16 single nucleotide polymorphisms (SNPs) in 10 non-HLA genes (IL7R, IL2RA, CLEC-16A, TYK2, CD58, IRF5, STAT3, CTLA-4, APOE, ICAM-1) in a Western Australian cohort of 350 MS patients and 498 population control subjects. Our results indicate that in this population, SNPs in IL7R, TYK2, IRF5 and APOE have modifying effects on MS susceptibility. We also found evidence of interactive protective effects between polymorphisms in the IL7R/CD58, CLEC-16A/CTLA-4, and TYK2/IRF5 genes, which in some instances are restricted within HLA- or gender-defined groups.

IL7Rα contributes to experimental autoimmune encephalomyelitis through altered T cell responses and nonhematopoietic cell lineages

A mutation in the IL7Rα locus has been identified as a risk factor for multiple sclerosis (MS), a neurodegenerative autoimmune disease characterized by inflammation, demyelination, and axonal damage. IL7Rα has well documented roles in lymphocyte development and homeostasis, but its involvement in disease is largely understudied. In this study, we use the experimental autoimmune encephalomyelitis (EAE) model of MS to show that a less severe form of the disease results when IL7Rα expression is largely restricted to thymic tissue in IL7RTg(IL7R-/-) mice. Compared with wild-type (WT) mice, IL7RTg(IL7R-/-) mice exhibited reduced paralysis and myelin damage that correlated with dampened effector responses, namely decreased TNF production. Furthermore, treatment of diseased WT mice with neutralizing anti-IL7Rα Ab also resulted in significant improvement of EAE. In addition, chimeric mice were generated by bone marrow transplant to limit expression of IL7Rα to cells of either hematopoietic or nonhematopoietic origin. Mice lacking IL7Rα only on hematopoietic cells develop severe EAE, suggesting that IL7Rα expression in the nonhematopoietic compartment contributes to disease. Moreover, novel IL7Rα expression was identified on astrocytes and oligodendrocytes endogenous to the CNS. Chimeric mice that lack IL7Rα only on nonhematopoietic cells also develop severe EAE, which further supports the role of IL7Rα in T cell effector function. Conversely, mice that lack IL7Rα throughout both compartments are dramatically protected from disease. Taken together, these data indicate that multiple cell types use IL7Rα signaling in the development of EAE, and inhibition of this pathway should be considered as a new therapeutic avenue for MS.

The human IL-7 receptor gene: deletions, polymorphisms and mutations

Most T cell subsets depend on IL-7 for survival. IL-7 binds to IL-7Rα and γc, initiating the signaling cascade. Deletion of IL-7Ra in humans has, for some time, been known to cause severe combined immunodeficiency. More recently, polymorphisms in IL-7R have been shown be a risk factor for a number of diseases that are autoimmune or involve excess immune and inflammatory responses including multiple sclerosis, type 1 diabetes, rheumatoid arthritis, primary biliary cirrhosis, inflammatory bowel disease, atopic dermatitis, inhalation allergy, sarcoidosis and graft-versus host disease. The polymorphism that affects risk to most of these immunopathologies is T244I at the border of the extracellular domain and the transmembrane region. The same region has recently been shown to harbor gain-of-function mutations in acute lymphoblastic leukemia. These studies have suggested new therapies that target the IL-7 pathway.

Cytokine gene polymorphisms and human autoimmune disease in the era of genome-wide association studies

Cytokine (receptor) genes have traditionally attracted great interest as plausible genetic risk factors for autoimmune disease. Since 2007, the implementation of genome-wide association studies has facilitated the robust identification of allelic variants in more than 35 cytokine loci as susceptibility factors for a wide variety of over 15 autoimmune disorders. In this review, we catalog the gene loci of interleukin, chemokine, and tumor necrosis factor receptor superfamily and ligands that have emerged as autoimmune risk factors. We examine recent progress made in the clarification of the functional mechanisms by which polymorphisms in the genes coding for interleukin-2 receptor alpha (IL2RA), IL7R, and IL23R may alter risk for autoimmune disease, and discuss opposite autoimmune risk alleles found, among others, at the IL10 locus.

A cytokine gene screen uncovers SOCS1 as genetic risk factor for multiple sclerosis

Cytokine and cytokine receptor genes, including IL2RA, IL7R and IL12A, are known risk factors for multiple sclerosis (MS). Excitotoxic oligodendroglial death mediated by glutamate receptors contributes to demyelinating reactions. In the present study, we screened 368 single-nucleotide polymorphisms (SNPs) in 55 genes or gene clusters coding for cytokines, cytokine receptors, suppressors of cytokine signaling (SOCS), complement factors and glutamate receptors for association with MS in a Spanish-Basque resident population. Top-scoring SNPs were found within or nearby the genes coding for SOCS-1 (P=0.0005), interleukin-28 receptor, alpha chain (P=0.0008), oncostatin M receptor (P=0.002) and interleukin-22 receptor, alpha 2 (IL22RA2; P=0.003). The SOCS1 rs243324 variant was validated as risk factor for MS in a separate cohort of 3919 MS patients and 4003 controls (combined Cochran-Mantel-Haenszel P=0.00006; odds ratio (OR)=1.13; 95% confidence interval (CI)=1.07-1.20). In addition, the T allele of rs243324 was consistently increased in relapsing-remitting/secondary progressive versus primary-progressive MS patients, in each of the six data sets used in this study (P(CMH)=0.0096; OR=1.24; 95% CI 1.05-1.46). The association with SOCS1 appears independent from the chr16MS risk locus CLEC16A.

Relevance of IL7R genotype and mRNA expression in Dutch patients with multiple sclerosis

Background: The interleukin 7 receptor (IL7R) has been recognized as a susceptibility gene for Multiple Sclerosis (MS). Analysis of rs6897932 (the most strongly MS-associated single nucleotide polymorphism (SNP)), showed effects of genotype on the relative expression of membrane-bound to total amount of IL7R mRNA.

Objective: We assessed the relevance of IL7R on MS phenotype (including clinical and magnetic resonance imaging (MRI) parameters) at DNA and mRNA level in Dutch patients with MS.

Methods: The genotype of rs6897932 was analyzed in 697 patients with MS and 174 healthy controls. The relevance of genotype and carriership of the C allele on MS phenotype (disease activity and severity, using clinical and MRI parameters) was assessed. In addition, relative gene expression of membrane-bound to total IL7R mRNA was analyzed with respect to disease phenotype in a subgroup of 95 patients with early relapsing MS.

Results: In particular, homozygosity for the risk allele is a risk factor for MS in our population (ORCC vs CT and TT = 1.65 (95% CI: 1.18–2.30), two-sided p = 0.004). However, no effect of genotype or the relative expression of membrane-bound IL7R (presence of exon 6–7) to total amount of IL7R mRNA (presence of exon 4–5) was found on MS phenotype.

Discussion: Homozygosity for the IL7R exon 6 rs6897932 C allele is associated with a higher risk for MS in our Dutch population. No effect was found of genotype or mRNA expression on disease phenotype.

Association between the IL7R T244I polymorphism and multiple sclerosis: a meta-analysis

Previously published analyses of the association between the interleukin 7 receptor (IL7R) T244I polymorphism (rs6897932) and multiple sclerosis (MS) have yielded conflicting results. We performed a meta-analysis to assess whether the combined data showed this association, and to investigate its effect size. We analyzed 10 studies identified from PubMed (12,185 MS patients and 15,855 controls) and calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for the C-allele, the C/C genotype (recessive effect) and the C/C + C/T (dominant effect) genotype. Heterogeneity within and between studies was observed: allele C: Q = 30.86, P = 0.002; genotype C/C: Q = 30.28, P = 0.003. Using a random-effects model, the C-allele and the C/C genotype were associated with MS (OR = 1.11, 95% CI = 1.04-1.19, P = 0.001 for the C-allele; OR = 1.15, 95% CI = 1.06-1.24, P = 0.0009 for the C/C genotype). The C/C + C/T genotype was also associated with MS using a fixed-effects model (OR = 1.15, 95% CI = 1.05-1.26, P = 0.003). There was no significant publication bias among the selected studies according to the funnel plot. We also performed the analysis on a European subgroup. This revealed an association between IL7R T244I and MS (P < 0.00001 for the C-allele and the C/C genotype; P = 0.0004 for the C/C + C/T genotype), no heterogeneity was observed (allele C: P = 0.07; genotype C/C: P = 0.10). In conclusion, the meta-analysis demonstrated that the IL7R T244I polymorphism was associated with susceptibility to MS.

Validation of the CD6 and TNFRSF1A loci as risk factors for multiple sclerosis in Spain

A recent meta-analysis of genome-wide association screens coupled to a replication exercise in a combined US/UK collection led to the identification of 4 single nucleotide polymorphisms (SNPs) in three gene loci, i.e. TNFRSF1A, CD6 and IRF8, as novel risk factors for multiple sclerosis with genome-wide level of significance. In the present study, using a combined all-Spain collection of 2515 MS patients and 2942 healthy controls, we demonstrate significant association of rs17824933 in CD6 (P(CMH)=0.004; OR=1.14; 95% CI 1.04-1.24) and of rs1860545 in TNFRSF1A (P(CMH)=0.001; OR=1.15; 95% CI 1.06-1.25) with MS, while the low-frequency coding non-synonymous SNP rs4149584 in TNFRSF1A displayed a trend for association (P(CMH)=0.062; OR=1.27; 95% CI 0.99-1.63). This data reinforce a generic role for CD6 and TNFRSF1A in susceptibility to MS, extending to populations of southern European ancestry.

Interleukin 7 receptor alpha polymorphism rs6897932 and susceptibility to multiple sclerosis in the Western Balkans

The interleukin 7 receptor alpha single nucleotide polymorphism rs6897932 was identified as a multiple sclerosis susceptibility-modifying polymorphism in genome-wide and gene scan studies, mainly in populations in western countries.

The aim of this study was to investigate the association of interleukin 7 receptor alpha rs6897932 with multiple sclerosis in populations from the Western Balkans: Serbia, Croatia, and Slovenia.

A total of 678 unrelated white patients and 597 unrelated, ethnically matched healthy controls were included in the study. Genotyping was performed by real-time polymerase chain reaction.

We found no significant difference in genotype or allele frequencies between controls and patients with multiple sclerosis either separately in Serbian, Croatian, and Slovenian populations or in the whole sample from the Western Balkans. The odds ratio for multiple sclerosis in this study was 1.04 (0.86—1.25) for the C allele.

It is known that demographic as well as environmental factors have a substantial role in multiple sclerosis development, as well as population genetic background. The results of this study indicate that other types of genome variants should be required for the development and/or progression of multiple sclerosis, which may vary among populations.

IL7RA polymorphisms and chronic inflammatory arthropathies

The C allele of a single nucleotide polymorphism (SNP), rs6897932, located in the interleukin-7 receptor alpha chain (IL7RA) was recently found to be associated with multiple sclerosis and Type I diabetes. We analysed 13 SNPs in the IL7RA gene in a combined cohort of patients with chronic inflammatory arthropathies (rheumatoid arthritis and juvenile idiopathic arthritis; 368 patients and 532 unaffected subjects). No significant associations with disease were found with the exception of the non-synonymous SNP rs6897932. This SNP showed modest enrichment of the TT genotype in arthritic patients compared with controls [P = 0.02; OR 1.72 (95% CI 1.08-2.75)]. Our data are suggestive for a role of rs6897932 in predisposition to chronic inflammatory arthropathies.

Multiple sclerosis and polymorphisms of innate pattern recognition receptors TLR1-10, NOD1-2, DDX58, and IFIH1

Genetic factors are critical in multiple sclerosis (MS), and it is conceivable that the pattern recognition receptors of the innate immune system are of pathogenic importance. We therefore developed two novel assays capable of analyzing 42 single-nucleotide polymorphisms in the human genes encoding TLR1-10, NOD1-2, DDX58, and IFIH1. Using these assays, we genotyped 963 MS patients and 960 controls, and analyzed for possible associations to MS diagnosis, clinical course, severity, and age at onset. Our results support previous findings of associations between the IFIH1-locus and MS (IFIH1-rs3747517 and IFIH1-rs1990760 trend test: P=0.002 and P=0.014, respectively).

Variation in the IL7RA and IL2RA genes in German multiple sclerosis patients

Variation in the genes encoding the interleukin (IL) 7 and IL2 receptor alpha chains (IL7RA, IL2RA) was recently found associated with multiple sclerosis (MS). We evaluated the role of these two genes in a large German MS case-control cohort. Five single nucleotide polymorphisms (SNPs) in IL7RA and four in IL2RA were genotyped in 1319 MS patients and 908 controls by means of restriction enzyme digestion or TaqMan assays and subsequently evaluated for association with MS. IL7RA expression was measured via quantitative real time PCR in 24 subjects. We replicated the association of exon 6 variation (rs6897932) in IL7RA with MS. Yet, this association was only found in patients with primary progressive (pp) or secondary progressive (sp) disease course (p=0.0004). Expression analysis did not show differences in IL7RA expression depending on genotypes at this locus, while reduced expression of the soluble receptor was observed in patients with pp and sp MS irrespective of genotype. In the IL2RA gene, significant associations of SNPs in introns 3 and 7 with MS subtypes were obvious. Together these results confirm involvement of polymorphisms in the IL7RA and IL2RA genes in MS pathogenesis and suggest that IL7RA variation may primarily affect chronic disease courses.

Use of a genetic isolate to identify rare disease variants: C7 on 5p associated with MS

Large case-control genome-wide association studies primarily expose common variants contributing to disease pathogenesis with modest effects. Thus, alternative strategies are needed to tackle rare, possibly more penetrant alleles. One strategy is to use special populations with a founder effect and isolation, resulting in allelic enrichment. For multiple sclerosis such a unique setting is reported in Southern Ostrobothnia in Finland, where the prevalence and familial occurrence of multiple sclerosis (MS) are exceptionally high. Here, we have studied one of the best replicated MS loci, 5p, and monitored for haplotypes shared among 72 regional MS cases, the majority of which are genealogically distantly related. The haplotype analysis over the 45 Mb region, covering the linkage peak identified in Finnish MS families, revealed only modest association at IL7R (P = 0.04), recently implicated in MS, whereas most significant association was found with one haplotype covering the C7-FLJ40243 locus (P = 0.0001), 5.1 Mb centromeric of IL7R. The finding was validated in an independent sample from the isolate and resulted in an odds ratio of 2.73 (P = 0.000003) in the combined data set. The identified relatively rare risk haplotype contains C7 (complement component 7), an important player of the innate immune system. Suggestive association with alleles of the region was seen also in more heterogeneous populations. Interestingly, also the complement activity correlated with the identified risk haplotype. These results suggest that the MS predisposing locus on 5p is more complex than assumed and exemplify power of population isolates in the identification of rare disease alleles.

The T244I variant of the interleukin-7 receptor-alpha gene and multiple sclerosis

Several but not all studies have provided evidence for the association between multiple sclerosis (MS) and the T244I variant of the interleukin-7 receptor-alpha gene (IL7RA), rs6897932. We performed a new replication case-control study in 599 MS patients and 594 healthy controls, all Caucasians from the south of Spain. The genotype and allele frequencies differed between MS cases and controls. The IL7RA rs6897932 C allele and the CC genotype were found to be factors for disease susceptibility [per allele odds ratio (OR) 1.32, 95% CI 1.1-1.6, P=0.0031; per CC genotype vs TT + TC genotypes, OR 1.5, 95% CI 1.18-1.87, P=0.0007]. The combined data analysis included 3324 cases and 5032 controls of Europeans and Americans of European origin resulting in stronger association with similar OR (P=1.9 x 10E-9). These findings in our sample support previous reported association studies between IL7RA rs6897932 and MS.