The Association Of Rapsyn Cene Promoter SNPs With Myasthenia Gravis

Objective:To explore whether the polymorphisms of receptor-associated protein at the synapse (rapsyn) gene promoter is associated with the clinical severity of patients with myasthenia gravis (MG), and whether the first exon-intron boundaries are genetically altered. The5single nucleotide polymorphisms (SNPs) sites in rapsyn gene promoter are marked as-189C>T,-116C> A,-101C>T,-72C>T,-52A> T. The genotype and allele frequency are analyzed to try to explore the relationship of gene polymorphisms with MG. This will lead to better understand the pathogenesis of MG. and to provide the basis for the diagnosis and gene therapy of MG.Methods:DNA was extracted from peripheral blood cells, sampled from36patients with MG and from53control individuals. All collected MG patients were diagnosed with standard, and other chronic diseases excluded. Autoimmune diseases and other chronic diseases were ruled out in control group too. The genes of promoter, the first exon, and the first exon-intron boundaries of rapsyn were amplified by PCR, then the products of PCR sequenced directly. Each sequence was compared with wild-type rapsyn gene and analysed. The chi-square test was used to test the Hardy-Weinberg equilibrium, and also performed to compare allelic frequencies of each SNP between MG patient and control groups.Results:The alleles of5polymorphisms in the promoter of rapsyn above were already up to genetic balance both in control group and MG patients. Gene and allele frequency in the two groups were not statistically different. No mutation was found in the first exon or at the exon-intron boundaries of MG patients.Conclusion:The5SNPs (-189C>T,-116C> A,-101C>T,-72C>T,-52A> T) in the promoter of rapsyn is not associated with the risk of MG. The genetic mutations are not found at the first exon and exon-intron boundaries. A large number of samples are needed to repeat due to the regional differences.