investigation of human apolipoprotein e polymorphisms in multiple sclerosis patients of Iran

ABSTRACT

Multiple sclerosis [MS] is a chronic inflammatory disorder of the central nervous system, with a complex etiology that includes a strong genetic component. The chromosome 19q13 region surrounding the apolipoprotein E [APOE] gene has shown consistent evidence of involvement in MS. In a cross-sectional study, to show the APOE genotype and allele frequency in the MS population of Iran in comparison with the control group, we genotyped its polymorphisms [sigma 2, sigma 3 and sigma 4 alleles]. The authors investigated 81 patients with clinically definite MS and 93 asymptomatic elderly volunteers. The frequency of the APOE allele in the MS population in comparison with controls was 9.3% vs. 0.5% for sigma 4, 44.4% vs. 51.6% for sigma 3, and 46.3% vs. 47.8% for sigma 2. The highest frequency of APOE genotype was from sigma 2/sigma 3 with 66.7% vs. 94.6% and the lowest, sigma 4/sigma 4 genotype with 2.5% vs. 0%. The authors found significant differences in the distribution of 84 allele between patients with MS and controls [9.3% vs. 0.5%; X[2]=15.2;df=2; p<0.001]. The highest frequency of sigma 4 allele in MS patients was in Pure Turkish [25.0% vs. 5.3%] ethnicity. There was no significant relation between ethnicity and genotype. In the present study sigma 2/sigma 4, sigma 3/sigma 4 and sigma 4/sigma 4 genotypes were more common in bout-onset cases compared to primary progressive cases, and the secondary progressive disease was higher in carriers of sigma 4 allele. Also, the sigma 2 allele was higher in relapsing remitting disease