Differences in the frequency of Alzheimer's disease-associated genomic variations in populations of different races

The general genetic background is important when studying major common diseases, such as Alzheimer's disease (AD). Determining the underlying genetic factors in populations of different races might allow for the tailored management of such diseases. The aim of the present study was to identify potential single-nucleotide polymorphisms (SNP) and genes associated with racial differences.

We identified AD-associated SNP with different carrier frequencies among races through the National Human Genome Research Institute and 1000 Genome Project databases. We generated heatmaps and carried out principle component analysis and pathway analysis. A total of 99 AD-associated SNP from genome-wide association studies were found to have different frequencies among races. Principle component analysis showed that specific SNP had higher or lower frequencies in specific races, and that similar races were clustered together.

Pathway analysis showed that a total of 15 pathways involving intracellular endocytosis, inflammation, immune response and lipid metabolism were significant, and that apolipoprotein E was involved in the most significant pathways. A literature review showed that 16 genes were involved in the pathogenesis of AD, and that the identified SNP could be used to cluster different races, suggesting that these SNP represented different genomic backgrounds of races.

As disease-associated genes might have several functional variants across different populations, these genes could be candidates for further studies, such as target gene sequencing or functional follow up of putative loci regarding racial differences. Geriatr Gerontol Int 2017; 17: 2184-2193.