Association study of the BIN1 and IL-6 genes on Alzheimer's disease

Abstract

Genome-wide association study (GWAS) has identified several novel genes associated with the risk of Alzheimer's disease (AD), which is a progressive neurodegenerative disease in elders. However, most of the novel genes have not been validated through replication in separated populations. Among them, the BIN1 gene is involved in endocytosis and intracellular trafficking as well as in the formation of β amyloid plaques and neurofibrillary tangles, which are the main pathological hallmarks of AD. The IL-6 gene has also been frequently associated with AD; however, consistent results have not been found. IL-6, a cytokine from the immune system, is implicated in the pathogenesis of several degenerative diseases. Similar to BIN1, it is suggested that IL-6 is also involved in the formation of β amyloid plaques. In this case-control study, we aimed to investigate whether single nucleotide polymorphisms in the BIN1 (rs744373) and IL-6 (rs1800795) genes are associated with AD. Genotype frequencies were evaluated via PCR-RFLP in 82 late-onset AD patients and 159 elderly healthy controls, who were matched by age and gender. In this study, no association was found for either polymorphism, suggesting that these genes are not implicated in the aetiology of AD in all populations.

Keywords: Alzheimer’s disease; Brazilian population; Case-control study; −174 G/C IL-6.