[Polymorphism A/G in position +49 of CTLA4 exon 1 in multiple sclerosis in Russians]

The association of multiple sclerosis (MS) with alleles A and G of the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene, a candidate gene for autoimmune disorders, was studied. The allele polymorphism results from single nucleotide substitution (A/G) in position +49 of exon 1 and leads to substitution Thr-->Ala in the leader peptide. The case-control study involved two groups of ethnic Russians: 168 MS patients and 209 healthy subjects from central Russia. Genotype frequencies were in agreement with the Hardy-Weinberg equilibrium in both groups (P > 0.05). The controls significantly differed in CTLA4 allele and genotype frequencies from Mongoloids but not from other Caucasians. No association was observed between MS and CTLA4. In addition, the combined association with MS was analyzed for both the CTLA4 alleles and allele groups of HLA DRB1. The results showed that the CTLA4 dimorphism does not affect susceptibility to MS in ethnic Russians, be these stratified or not with regard to DRB1 alleles corresponding to serologic specificities DR1 to DR16.