Associação entre polimorfismos dos genes AKT1, AKTIP, OX2R, PER2, PER3 e CLOCK em idosos com depressão de início tardio ou doença de Alzheimer

Abstract

Depression is a disease with the highest prevalence in the population, affecting about 20% of individuals throughout life. When the first episode affects individuals older than 65 years is considered late-onset depression (LOD). The elderly population has increased significantly in Brazil and is estimated to reach, by 2025, about 32 million individuals. Alzheimer's Disease (AD) and depression are highly prevalent diseases in the elderly population and determine high rates of disabilities. Previous studies suggest that depression, especially LOD, may represent a risk factor for AD or an early manifestation of the disease. It has been suggested an association between circadian genes in the pathology of LOD and AD due to sleep-wake alterations. We conducted a study involving individuals: control group (112), DA (249), LOD (222), with 19 SNPs (7 AKT1, 2 AKTIP, 2 PER3, 1 PER2, 1 CLOCK and 6 OX2R. Participants were assessed according to DSM-IV, MINI-PLUS and Geriatric Depression Scale (GDS) for LOD and NINCDS-ADRDA criteria for AD. Our results suggest an association between rs3730358 homozygous T/T and LOD. In the alleles analysis, the tagSNPs rs7741664 and rs2134294, both OX2R, showed allele C association with LOD. The rs2134294 C/C genotype also showed LOD association, with odds ratio of 2.1. For other markers studied no association was found. This study is the first to establish the association of AKT1 and OX2R genes in LOD.