APOE Allele Frequency in Southern Greece: Exploring the Role of Geographical Gradient in the Greek Population

Abstract

Background: the apolipoprotein e4 allele (APOE4) constitutes an established genetic risk factor for Alzheimer’s Disease Dementia (ADD). We aimed to explore the frequency of the APOE isoforms in the Greek population of Southern Greece. Methods: peripheral blood from 175 Greek AD patients, 113 with mild cognitive impairment (MCI), and 75 healthy individuals. DNA isolation was performed with a High Pure PCR Template Kit (Roche), followed by amplification with a real-time qPCR kit (TIB MolBiol) in Roche’s Light Cycler PCR platform. Results: APOE4 allele frequency was 20,57% in the ADD group, 17.69% in the MCI group, and 6.67% in the control group. APOE3/3 homozygosity was the most common genotype, while the frequency of APOE4/4 homozygosity was higher in the AD group (8.60%). APOE4 carrier status was associated with higher odds for ADD and MCI (OR: 4.49, 95% CI: [1.90–10.61] and OR: 3.82, 95% CI: [1.59–9.17], respectively). Conclusion: this study examines the APOE isoforms and is the first to report a higher APOE frequency in MCI compared with healthy controls in southern Greece. Importantly, we report the occurrence of the APOE4 allele, related to ADD, as amongst the lowest globally reported, even within the nation, thus enhancing the theory of ethnicity and latitude contribution.

Exploring the Genetic Landscape of Mild Behavioral Impairment as an Early Marker of Cognitive Decline: An Updated Review Focusing on Alzheimer’s Disease

“…In this context, MBI-affective dysregulation has been recently related to an increased risk of dementia among Black individuals compared to White ones [ 48 ]. Even among the same race or country, the frequency of genetic variants may vary, such as in the case of APOE e4 whose prevalence seems to depend at least partially on geographical gradient [ 93 ], which could affect epidemiological results.…”

"Investigation of ARMS2 and CFH Polymorphisms Associated with Age-Related Macular Degeneration in Alzheimer’s Disease Patients. A Greek Cohort Study"

“…CFH genotyping for coding SNP rs1061170, (GRCh38, chr1-196690107 C>T, NG_007259.1 g.43097C>T, NM_000186.4 c.1204C>T), that results in the missense substitution of histidine to a tyrosine amino acid at position 402 of the CFH protein (p.Y402H) was performed by our novel real-time qPCR-melting curve analysis developed by our research group on the LightCycler platform (Roche) as described previously [22] ARMS2 genotyping for coding SNP rs10490924 (GRCh38, chr10-122454932 G>T, NG_011725.1 g.5270G>T, NM_001099667.3 c.205G>T), that results in the missense substitution of alanine to a serine amino acid at position 69 of the ARMS2 protein (p.A69S) was performed by applying a literaturebased PCR-RFLP method with PvuII restriction [23][24]. Additionally, Volume 49-Issue 5 DOI: 10.26717/BJSTR.2023.49.007855 in all samples, APOE genotyping was performed with the LightMix APOE C112R R158C kit by TIB MolBiol in the LightCycler platform (Roche) as described in Papastefanopoulou, et al [25] in order to detect the E4 risk allele for Alzheimer's Disease (GRCh38, rs429358, chr19-44908684 T>C, NG_007084.2 g7903T>C, NM_000041.4 c.388T>C) that results in the missense substitution of cysteine to an arginine amino acid at position 130 of the APOE protein (p. C130R or 112 of the secreted protein) for the development of AD disease.…”