Study on the Association between SOAT1 Polymorphisms, Alzheimer’s Disease Risk and the Level of CSF Biomarkers

Background: In Alzheimer’s disease (AD) the beta-amyloid precursor protein is excessively cleaved into Aβ 42 , causing the abundant amyloid plaque loads in affected brain areas. Sterol O-acyltransferase 1 (SOAT1) has been found to regulate the production of beta-amyloid precursor protein. Methods: Wegenotyped 4 SOAT1 single nucleotide polymorphism (SNP) sites (rs2247071, rs2862616, rs3753526 and rs1044925) in 410 Finnish AD cases and 455 controls and conducted a single allele and genotypic distribution comparison as well as estimating the haplotype frequencies between cases and controls and the level of biomarkers in genotype and haplotype carriers. Results: The CC genotype of rs2247071 was overrepresented in the AD cases (OR = 1.38, 95% CI = 1.01–1.89, p = 0.043, Bonferroni corrected p = 0.172 with 4 tests) independent of gender, age and APOE Ε4 allele carrier status. We did not find any significant differences between Aβ 42 , tau or ptau levels in different allele, genotype or haplotype carrier cases. Conclusion: Our findings suggest that SOAT1 gene may possibly be only a minor risk factor in AD.