This study suggested that the IL7R C allele was associated with an increased risk of MS and larger-scale studies of populations are needed to explore the roles played by the IL7R T244I polymorphism during the pathogenesis of MS.
The study suggested that among Chinese Han population in southeastern China, the variant of IL-7RA (rs6897932) was associated with NMO especially NMO-IgG positive patients while the variant of IL-7 (rs1520333) with MS patients.
The T-allele in the single nucleotide polymorphism rs6897932 in the gene encoding the IL-7 receptor α (IL7RA) is associated with reduced risk of autoimmune diseases including multiple sclerosis and also affects the course of HIV infection.
In addition, the significant association between PrMS and rs6897932 indicates that IL7R may not be disease-causing but a determinant of disease course.
In addition, whereas no association was found between the alternative splicing SNP, rs6897932, and MS, a significant link was found between the promoter SNP, rs11567685, and MS.
Former studies demonstrated the single nucleotide polymorphism (SNP) rs6897932 C/T in the IL-7 receptor (IL-7R) gene was associated with susceptibility to autoimmune diseases, including multiple sclerosis and type I diabetes.
The levels of sIL-7Rα increased dose-dependent upon rs6897932 [C] risk allele carriership in both HCs and MS. Next, we hypothesized that lower sIL-7Rα could result in a higher mIL-7Rα to soluble IL-7Rα ratio.
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).
For MS, one of the first discoveries to emerge in this new era was the association with rs6897932[T244I] in the interleukin-7 receptor alpha chain (IL7RA) gene (Gregory et al. in Nat Genet 39(9):1083-1091, 2007; International Multiple Sclerosis Genetics Consortium in N Engl J Med 357(9):851-862, 2007; Lundmark in Nat Genet 39(9):1108-1113, 2007), a discovery that was accompanied by functional data that suggest this variant is likely to be causative rather than a surrogate proxy (Gregory et al. in Nat Genet 39(9):1083-1091, 2007).
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.
It is estimated that the C allele of a single nucleotide polymorphism, rs6897932, within the alternative spliced exon 6 of IL7RA is involved in about 30% of MS cases.