Genetic Susceptibility to Multiple Sclerosis: The Role of FOXP3 Gene Polymorphism.

Introduction: It is well recognized that both genetic and environmental factors play an important role in the pathogenesis of multiple sclerosis (MS). Immune pathogenesis of MS focuses on pathogenic CD4+ T lymphocytes. CD4+CD25+ regulatory T cells have suppressive function in this cell group. FOXP3 (forkhead boxP3) transcription factor is a key structure in the development and function of regulatory cells. Functional alterations in FOXP3 gene expression have been observed in various autoimmune diseases.

Methods: We screened a non-synonymous coding single nucleotide polymorphism (exon +2710 C/T) (rs2232369) of human FOXP3 gene in 148 MS patients (118 with Relapsing Remitting MS, 30 with Secondary Progressive MS) and 102 age- and sex-matched healthy controls. The association of polymorphisms with susceptibility, and course of the disease was evaluated.

Results: We could not detect any single nucleotide polymorphism in MS patients, however, polymorphic allele was detected in 3% of the control group. Consequently, a genetic association between the FOXP3 gene polymorphism and MS was not revealed.

Conclusion: The distribution of this polymorphism has not been screened in any other MS populations before. Although we could not succeed to find any association between susceptibility to MS and screened FOXP3 gene polymorphisms, we suggest that this particular polymorphism is not appropriate for these kind of studies in the future.