Tumor necrosis factor-alpha polymorphism and susceptibility to multiple sclerosis in the Iranian population.

Background: Multiple sclerosis (MS) is an immune-mediated disease of polygenic etiology. Tumor necrosis factor-α (TNF-α) microsatellite as a proinflammatory cytokine is believed to play an important role in the etiology of this disease.

Objectives: The aim of this study was to investigate the association of TNF-α microsatellite sequence variation in patients with MS and its risk factor in the southern Iranian population.

Patients and methods: This polymorphism was investigated in an Iranian population of 163 native southern people [81 patients with MS according to the poser criteria and 82 healthy controls (HC) with the same age, sex, social, ethnical and geographical features (Hormozgan and Fars provinces)]. All the controls were nonimmunological, neurological patients. All the cases and controls were chosen randomly and genotyped for polymorphism of TNF-α microsatellite.

Results: The frequencies of TNF-α*11 (0.25, P < 0.005) and TNF-α*10 (P < 0.005) alleles increased in patients with MS compared with controls, showing a significant difference among the studied population.

Conclusions: The current study adds evidence to the association of TNF-α gene polymorphism and MS in this southern south Iranian population which is consistent with the genetic analysis of MS in Europeans (GAMES) project reports and these two alleles reported in this study may be one of the genetic risk factor for MS. Furthermore, this data can be used to build the Iranian gene bank for future studies.