Apolipoprotein E polymorphisms status in Iranian patients with multiple sclerosis

Background: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system. Evidences linking apolipoprotein E (APOE) to myelin repair, neuronal plasticity, and cerebral inflammatory processes suggest that it may be relevant in MS. The main goal of this study was to determine whether the APOE genotypes and alleles are associated with MS patients.

Materials and methods: In total, 147 MS cases and 168 control subjects from Iranian population were genotyped for APOE gene using PCR-RFLP method.

Results: The frequency of APOE-ε2ε3 genotype was significantly higher in controls than cases (14.3% vs. 6.1%, P=0.009, OR=0.39) whereas APOE-ε3ε4 genotype frequency was significantly higher in cases compared with controls (8.2% vs. 3.6%, P=0.03, OR=2.4). APOE-ε2 allele frequency in cases was significantly lower than that of controls (4.4% vs. 8.0%, P=0.03, OR=0.52). Also male controls were significantly more likely to have APOE-ε2 allele (7.8% vs. 1%, P=0.01, OR=0.11). APOE-ε4 allele frequency in cases was significantly higher than control group (4.8% versus 2.1%, P=0.03, OR=2.35).

Conclusion: It seems that individuals carrying APOE-ε4 allele and/or APOE-ε3ε4 genotype develop MS two times more than non-carriers. Also APOE-ε2ε3 genotype or APOE-ε2 allele may have a protective role against MS development in Iranian population. Further investigation would be warranted to understand the role of APOE alleles and genotypes and risk of MS.