Vitamin D receptor gene polymorphisms in Alzheimer's disease patients

The aim of this study was to determine whether polymorphisms of the VDR gene may increase the risk of Alzheimer disease (AD) development in Lower Silesian patients in comparison with other populations.

108 AD patients (aged 73.7±8.6) vs 77 healthy volunteers (aged 64.5±7.8) in the Lower Silesian population were studied. We investigated the frequency of the VDR polymorphisms rs731236 (TaqI), rs7975232 (ApaI), rs10735810 (FokI) and rs1544410 (BsmI) in the AD group vs the healthy group. Afterwards, MEDLINE and ResearchGate were studied to compare our investigation with other populations, due to the relatively small group size in our study.

We did not observe any significant differences in frequency of genotypes of rs731236 (TaqI), rs10735810 (FokI) or rs1544410 (BsmI) VDR polymorphisms between the two Lower Silesian groups. Frequency of allele A of ApaI in the control group was significantly higher vs AD patients (p<0.0177) in the Lower Silesian population. Furthermore the difference in the occurrence of allele t in TaqI and allele A in ApaI between AD patients vs the control group was significant (respectively p<0.0056, p<0.0140) in British Europeans. This observation may suggest that allele "a" of the ApaI polymorphism is a risk allele in AD Lower Silesian patients. We compared our results with those obtained for the population of British Europeans. In multivariate stepwise regression, allele "A" of ApaI was associated with 30% lower risk of AD (OR=0.70, p=0.0009) in total treated Polish and British populations. We did not observe similar results in Turkish and Iranian populations.

Our data suggest that the allele "A" VDR genotype of ApaI reduces AD risk, probably depending on ethnic origin and climatic conditions.