Progression From Amnesic Mild Cognitive Impairment To Alzheimer'S Disease: Esr1 And Esr2 Polymorphisms And Apoe Gene

Background: Many genes have been studied to determine how they might be involved in Alzheimer's disease (AD). Estrogens have a protective effect in the central nervous system. The mechanisms of action of estrogens are mediated by two estrogen receptors (ERs), ER alpha and ER beta. Thus, these genes could also play a role in the progression of amnesic mild cognitive impairment (MCIa) to AD. The aim of this study was to examine the role of ER single nucleotide polymorphisms (SNPs) as a risk factor for MCIa, as well as the interaction with apolipoprotein E (APOE) epsilon 4 in the progression to AD. Methods: 79 MCIa patients and 138 healthy controls were analyzed. SNPs were genotyped via restriction fragment length polymorphisms and real-time PCR, RT-PCR or RT-PCR (TaqMan) assays. Results: There is a lack of association between MCIa patients who converted to AD and ER SNPs. APOE epsilon 4 allele is an independent risk factor of MCIa (OR = 1.86; 95% CI = 1.02- 3.38, p = 0.042) with a high prevalence in converted subjects. APOE epsilon 4 is able to predict the progression from MCIa patients to AD (OR = 2.55; 95% CI = 1.20-5.42, p = 0.015). Conclusions: The presence of the APOE epsilon 4 allele, and not the alleles of ER SNPs, is a risk factor for MCIa. Furthermore, APOE genotype seems to predict the conversion from MCIa to AD. Copyright (C) 2012 S. Karger AG, Basel