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

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