Vitamin D Receptor (VDR) Polymorphisms and Late-Onset Alzheimer's Disease: An Association Study

Abstract

Background: Late-onset Alzheimer's disease (AD), a genetically heterogeneous neurodegenerative disorder, is the most common form of dementia in people over 65 years old. The role of vitamin D in neuropsychiatric and neurodegenerative disorders such as AD has been supported by epidemiologic investigations and animal models, as well. We examined the association of the vitamin D receptor (VDR) gene polymorphisms and late-onset AD in an Iranian population.

Methods: This study was performed in Tehran, Iran from 2007 to 2008. Totally, 145 AD patients and 162 age-matched unrelated healthy controls were included. The genotype and allele frequencies for the VDR polymorphisms, ApaI (G>T; rs7975232) and TaqI (C>T; rs731236), were determined in the case and control subjects PCR-RFLP analysis. Logistic regression analysis was performed to assess the effect of mutant genotype or allele in the study groups.

Results: The statistical analyses showed significant differences neither in genotype nor in allele frequencies of the ApaI and TaqI polymorphisms between the case and control groups.

Conclusion: It seems that the ApaI and TaqI polymorphisms are not associated with the risk of late-onset AD in Iranian population.

Keywords: Alzheimer’s Disease; Association Study; Iran; PCR-RFLP; Polymorphism; Vitamin D Receptor.