About genotype and allele distributions of APP promoter single-nucleotide polymorphisms

Background. Alzheimer’s disease is caused by progressive degeneration of the central nervous system and is the most prevalent form of dementia in the elderly. The -amyloid precursor protein (-APP or APP), which generates the neurotoxic amyloid beta, appears to play an important role in the pathogenesis of Alzheimer’s disease. The purpose of the study is to determine the APP gene polymorphism in individuals with Alzheimer’s disease and a control group. Materials and methods. The study is approved by the Ethics Committee of Medcenter Clinic (Batumi, Georgia) and was conducted there. It had a case-control design. Sixty-seven Alzheimer patients were recruited. The control group (n = 50) consisted of healthy, age-matched individuals. Both parties were asked to sign an informed consent form, and their clinical information was obtained from medical charts. The mean age for cases were 68.00 ± 9.43 years, whereas control subjects had a mean age of 65.0 ± 10.2 years. Results. In this study, the rs463946 polymorphism in the APP gene was analyzed. Demographic characteristics of cases and controls were investigated. The average age of cases (68 years) was slightly higher than that of controls (65 years), although this difference does not reach statistical significance (p = 0.11). Under the codominant model, the odds ratio (OR) of 0.45 (CC vs. GC) suggest that individuals with the CC genotype have lower odds of being a case compared to those having the heterozygote (GC), but this difference is not statistically significant (p = 0.27). The OR of 2.49 (GG vs. GC) indicates that individuals with the GG genotype have significantly higher odds of being a case compared to those with the heterozygote (GC) (p = 0.04). In addition, the OR (C vs. G) indicates that the C allele is less frequent in cases (p = 0.043). These results support the hypothesis that the C allele (when present in one copy) has a protective effect. Conclusions. The obtained data is noteworthy. Genetic research into dementia continues to help many people around the world. These data require further research using larger population samples of different age categories.