Genetic studies on late-onset Alzheimer's disease (AD) have repeatedly mapped susceptibility loci onto chromosome 12q13, encompassing the vitamin D receptor (VDR) gene. Epidemiology studies have indicated vitamin D insufficiency as a risk factor for AD. Given that VDR is the major mediator for vitamin D's actions, we sought to clarify the role of VDR in late-onset AD. We conducted an association study in 492 late-onset AD cases and 496 controls with 80 tagging single nucleotide polymorphisms (SNPs). The strongest association was found at a promoter SNP rs11568820 (P = 9.1×10(-6), odds ratio (OR) = 1.69), which resides within the transcription factor Cdx-2 binding site and the SNP has been also known as CDX2. The risk-allele at rs11568820 is associated with lower VDR promoter activity (p < 10(-11)). The overexpression of VDR or vitamin D treatment suppressed amyloid precursor protein (APP) transcription in neuroblastoma cells (p < 0.001). We provide both statistical evidence and functional data suggesting VDR confers genetic risk for AD. Our findings are consistent with epidemiology studies suggesting that vitamin D insufficiency increases the risk of developing AD.
Wang L, Hara K, Van Baaren JM, Price JC, Beecham GW, Gallins PJ, Whitehead PL, Wang G, Lu C, Slifer MA, Züchner S, Martin ER, Mash D, Haines JL, Pericak-Vance MA, Gilbert JR. Vitamin D receptor and Alzheimer's disease: a genetic and functional study. Neurobiol Aging. 2012 February Hussman Institute for Human Genomics, University of Miami Miller School of Medicine (1501) NW 10 Ave, Miami, Florida, USA.