association between sporadic Alzheimer's disease and the human ABCA1 and APOE gene polymorphisms in Iranian population

Apolipoprotein E [APOE], which its epsilon4 allele has been reported as a risk factor in late onset Alzheimer's disease [AD], is the main cholesterol carrier in the brain. ATP-binding cassette transporter A1 [ABCA1] gene on chromosome 9, which has been known by genome-wide AD linkage study, has an important role in cellular cholesterol efflux. This study determines the association between sporadic AD and the human ABCA1 and APOE gene polymorphisms in Iranian population. 154 AD cases and 162 control subjects from Iranian population were genotyped for APOE genotypes and ABCA1 polymorphism [R219K]. The frequency of epsilon2epsilon3 genotype was higher in control subjects comparing AD patients but was not significant [13% versus 5.8%] and epsilon3epsilon4 genotype frequency was significantly higher in AD cases comparing with control subjects. APOE-epsilon2 allele frequency in cases was lower than control subjects but this difference was not significant [4.5% versus 8%]. Individuals carrying epsilon4 allele, developed AD 6.5 times more than non-carriers [OR=6.52, 95%CI=2.63-16.17]. There was no significant association between ABCA1 polymorphism and AD. Unlike other studies, R219K polymorphism was not dependent on gender and APOE-epsilon4 allele and there was no association between APOE and ABCA1 in AD patients compared to controls

Association between alzheimer's disease and apolipoprotein E polymorphisms

Alzheimer's disease as a neurodegenerative disorder is the commonest type of dementia. A growing number of genes have been reported as the risk factors, which increase the susceptibility to Alzheimer's disease. Apolipoprotein E [APOE], which its 4 allele has been reported as a risk factor in late onset Alzheimer's disease [AD], is the main cholesterol carrier in the brain. The main goal of this study was to assess the role of APOE genotypes and alleles in AD in Iranian population. This study was performed in Tehran, Iran from 2007 to 2008. Totally, 154 AD cases and 162 control subjects from Iranian population were genotyped for APOE using PCR method. Genotype and alleles frequencies for APOE were calculated and compared between AD case and control subjects by epsilon 2 or Fisher's exact test. Type one error assumed less than 0.05. The frequency of epsilon 2 epsilon 3 genotype was significantly higher in control subjects than AD patients was [13.5% versus 5.2%, P<0.05] and epsilon 3 epsilon 4 genotype frequency was significantly higher in AD cases compared with control subjects. APOE-epsilon 2 allele frequency in cases was lower than that of control subjects but this difference was not significant [4.2% versus 7.7%]. It seems that individuals carrying epsilon 4 allele, develop AD 6.5 times more than non-carriers do [OR=6.566, 95% CI=2.89-14.92]. It has been reported that epsilon 4 allele acts in dose-age-dependent manner but we have shown that the risk of developing AD in male APOE-epsilon 4 allele carriers is higher than that of female epsilon 4 carriers