Genetic association between ghrelin polymorphisms and Alzheimer's disease in a Japanese population.

BACKGROUND/AIMS: Ghrelin has been reported to enter the hippocampus and to bind to the neurons of the hippocampal formation. This peptide also affects neuronal glucose uptake and decreases tau hyperphosphorylation. There is increasing evidence suggesting an association between ghrelin and Alzheimer's disease (AD) pathology. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) of the ghrelin gene are associated with AD.
METHODS: The SNPs were genotyped using TaqMan technology and were analyzed using a case-control study design. Our case-control dataset consisted of 182 AD patients and 143 age-matched controls.
RESULTS: Hardy-Weinberg equilibrium and linkage disequilibrium analyses suggest that the region in and around the gene is highly polymorphic. One SNP, rs4684677 (Leu90Gln), showed a marginal association with age of AD onset. We did not detect any association between the other SNPs of the ghrelin gene and AD.
CONCLUSION: There have been few genetic studies on the relationship between circulating ghrelin and functional SNPs. Further multifactorial studies are needed to clarify the relationship between ghrelin and AD.