Tehran University Medical Journal

Background: Multiple sclerosis (MS) is a chronic inflammatory disorder of the CNS characterized by destruction of the myelin sheath, gliosis and progressive neurological dysfunction. The regulatory T (Treg) cells play a major role in the control of the autoimmunity and inflammation. The forkhead box p3 (FOXP3) is a central molecule in the function of Treg cells that play an important role in the immunoregulation. The aim of this study was to investigation single nucleotide polymorphism (SNP), rs2232365, in FOXP3 gene in patients with multiple sclerosis.

Methods: In a case-control study, peripheral blood samples were collected from 90 patients with MS (46 men and 94 women with different patterns of disease) from January 2014 to April 2015 in the Afzalipoor Hospital, Kerman (a city located in the southeast of Iran). In a total, 90 healthy subjects were also enrolled into the investigation as a control group. The healthy subjects were recruited among blood donations of the Kerman Transfusion Organization and interviewed regarding CNS disease, and none of them had any history of CNS diseases or other relevant disorders. The SNP rs2232365 in FOXP3 gene was assessed by single specific primer-polymerase chain reaction (SSP-PCR) method. Finally, statistical analysis was performed using SPSS version 22 (Chicago, IL, USA).

Results: In both patients and healthy control groups, there was significant difference among subjects with GG, AG, and AA genotypes at rs2232365 in FOXP3 gene. The frequencies of AA and AG genotypes at rs2232365 in the FOXP3 gene were significantly higher in MS group as compared with healthy subjects (P<0.002). Moreover, the frequency of GG genotype was significantly lower in the MS group in comparison with healthy control subjects (P<0.002). The frequency of A allele was significantly higher whereas the frequency of G allele was significantly lower in MS patients as compared with healthy subjects (P<0.001).

Conclusion: The results of the present study suggest that SNP rs2232365 may influence the susceptibility to multiple sclerosis. Therefore, SNP rs3761548 may directly or indirectly alter the level of the FOXP3 protein expression in Treg cells.