title: Association study of four polymorphisms in the interleukin-7 receptor alpha gene with multiple sclerosis in Eastern Iran.
abstract: OBJECTIVE
  Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system (CNS) with unknown etiology. Various genetics and environmental factors contribute to the pathogenesis of the disease. The interleukin-7 receptor alpha chain (IL-7Ra) was identified as the first non-major histocompatibility complex (non-MHC) MS susceptibility locus. In this study we are trying to find the association of IL-7Ra gene polymorphisms with MS susceptibility in Eastern Iran.
  
  
  METHODS
  A case-control study was performed in two provinces Sistan & Baluchistan and Khorasan with 219 patients and 258 unrelated matched healthy controls, using PCR-RFLP method for four single nucleotide polymorphisms (SNPs) rs7718919, rs11567685, rs11567686 and rs6897932 of IL-7Ra gene.
  
  
  RESULTS
  We found a tendency toward association with genotyping analyses in SNP rs7718919 (P=0.048, OR=4.344, and 95% CI=0.892-21.146); also genotype and allele frequency in gender and MS subtype stratification were shown to have significant association with MS. Analysis of two provinces separately showed a significant difference in results of the allele and genotype frequencies. Moreover, haplotyping analysis showed that (GTGC) has an association only in the male secondary-progressive multiple sclerosis (SPMS) patients in comparison to the healthy controls (P=0.043, OR=0.413, and 95% CI=0.179-0.955).
  
  
  CONCLUSIONS
  IL7-Ra could be a susceptible gene to MS within the Eastern Iran population especially after MS and gender stratification.
authors.affiliation: Health Research Institute, Infectious and Tropical Disease Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran ; Virology Department, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Mehrdad Sadeghi
authors.initials: MS
authors.lastname: Haj
authors.affiliation: Department of Medical Biotechnology & Molecular Sciences, Faculty of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran ; Esfarayen Faculty of Medical Sciences, Esfarayen, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Nikravesh
authors.affiliation: Department of Basic Sciences, Gonabad University of Medical Sciences, Gonabad, Iran ; Department of Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Majid Pahlevan
authors.initials: MP
authors.lastname: Kakhki
authors.affiliation: Department of Medical Biotechnology & Molecular Sciences, Faculty of Medicine, North Khorasan University of Medical Sciences, Bojnurd, Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Rakhshi
keywords: Association study; Haplotype; Interleukin-7 receptor alpha Multiple sclerosis; SNPs