Two single-base polymorphisms in the human tumor necrosis factor locus of multiple sclerosis patients from the Russian population: NcoI-RFLP in the first intron of the human lymphotoxin alpha gene correlates with the disease

Frequency of alleles and genotypes of two polymorphous sites in the locus o f turner necrosis factors (TNF) was determined in 50 multiple sclerosis (MS ) patients and 50 volunteers. Analysis of polymorphism in position -308 of the TNF alpha gene promoter region was carried out using allele-specific PC R. No reliable difference was found in the TMF alpha-308 allele distributio n between patients and control group. Analysis of NcoI-RFLP in the first in tron of lymphotoxin alpha (alias TNF beta) was done by the PCR-RFLP techniq ue. The reliable increase in the frequency of the rarer allele n2 was found in MS patients. No linkage disequilibrium of the n2 allele with some MS ma rkers, including DR2(15), was found. A possible role of the G-252 --> A poi nt mutation in the NcoI restriction site of the first intron of the lymphot oxin alpha gene in the genetic predisposition to MS is discussed.