APOE Allele Frequency in Southern Greece: Exploring the Role of Geographical Gradient in the Greek Population (original) (raw)
Related papers
Neuroscience Letters, 2005
The genotype of apolipoprotein E was examined in 173 sporadic Alzheimer's disease (AD) patients, 132 with late onset (LOAD) and 41 with early onset (EOAD), and in 174 healthy matched controls from Sicily. Despite a low frequency of the 4 allele (6.3%, 95% CI: 4.2-9.4) in controls, 4 allele was a stronger predictor of AD risk (odds ratio: 5.8, 95% CI: 3.5-9.4; p < 0.0001) than in most of the studies performed in other regions of Italy, and it has no influence on age at onset. 4/4 and 4/3 genotypes were similar predictors of AD risk. Conversely, a decreased risk was found in 3 allele carriers (odds ratio: 0.3, 95% CI: 0.2-0.4; p < 0.0001), which remained significant when considering EOAD cases only (odds ratio: 0.2, 95% CI: 0.1-0.4, p < 0.0001). In conclusion, differences in association strength of 4 allele with AD between Sicily and other regions of Italy suggest an influence of complex gene-gene and gene-environment interactions.
Association between apolipoprotein E polymorphism and Alzheimer disease in Tehran, Iran
Neuroscience Letters, 2005
Epsilon 4 allele of apolipoprotein E (APOE-4) is a major risk factor for Alzheimer's disease (AD). The association of APOE allele frequencies with AD remains unknown in developing countries. We examined the frequency of APOE alleles in 105 patients with AD and 129 cognitively normal subjects of similar age and sex (control group), in Tehran, Iran. The APOE-4 allele frequency was significantly higher in the AD subjects than in the control group (21% versus 6.2%, p < 0.001). In addition, the OR for APOE-4 heterozygous and homozygous subjects were 3.2 (p = 0.001) and 12.75 (p = 0.01), respectively. The OR was not uniform across age groups. The AD subjects carrying one or two APOE-4 allele showed earlier age-at-onset (p < 0.001). These data suggest that the APOE-4 allele increase the risk for AD in Tehran population in a dose and age-dependent manner. Although the APOE-2 allele frequency was lower in the AD subjects than in the control group (0.95% versus 2.7%, p = 0.15), APOE-2 was not associated with the onset of AD in Tehran's population. The OR for 2 allele in AD subjects was 0.34 (p = 0.21). The genotype frequencies for 3, 4, and 2 alleles in control subjects were 91.2, 6.1, and 2.7%, respectively. These values were similar to that reported for Turkish, Greece, Japanese, Spanish, and Moroccan populations, but they were significantly different from the reported values for the other ethnic populations. This observation emphasizes the importance of geographical location and ethnical background of the subjects in the study of APOE genotypes and their association with AD.
Apolipoprotein E4 allele frequency in Spanish Alzheimer and control cases
Neuroscience Letters, 1995
We have found an APOE e4 allelic frequency of 0.289 in Spanish AD patients (n = 88; average age = 71.2 _+ 9.37) and of 0.061 (95% CI 0.023-0.099) in age-matched controls (n = 147; average age = 71.5 _+ 10.29). Remarkably no ApoE 4/4 subjects were observed in any of the age-matched control groups compared to a total of 22 AD patients with the ApoE 4/4 phenotype. The combined odds ratio for subjects with one or two E4 alleles in the present study is 6.25 (95% CI 3.13-12.60), which is one of the highest so far reported. Altogether our results suggest a trans-European difference in the ApoE e4 frequency but no differences in the strength of the association between APOE4 and AD.
Neurochemical Research, 2005
Apolipoprotein E gene (Apoε) has three common alleles (ε2, ε3, and ε4), of which ε4 has been shown to be associated with an increased risk for Alzheimer’s disease (AD). Possible additional genetic factors, like the −491A variant of ApoE promoter may modify the development of AD, independently of the ApoE allele status. The objective of this study was to investigate whether A/T allelic polymorphism at site−491 of the ApoE promoter is associated with AD in a Hungarian population. The genomic DNA isolated from peripheral blood lymphocytes of 52 late-onset AD and 53 control individuals was used as a template for the two examined polymorphisms and PCR assay was applied. The ε4 allele was significantly over-represented in the AD group (28%) as compared with the control population (7%). No significant differences have been found between the control and the AD populations regarding the occurrence of the promoter A allele frequencies (control: 77%, AD: 70%). However, the AA genotype was more frequent in the AD group (48%) than in the control (10%) when the presence of ε4 allele was also considered. It is unlikely therefore that the −491A variant of the ApoE promoter gene is an independent risk factor in the Hungarian AD population, but a linkage disequilibrium exists between the two examined mutations.
ApoE polymorphism in Polish patients with Alzheimer's disease
Acta neurobiologiae experimentalis, 1998
Alzheimer's disease is a genetically heterogeneous disorder of CNS. The presence of APOE-epsilon 4 allele is known to increase the risk of early and late onset sporadic and late onset familial forms of AD. In various Western European countries, USA, Canada, Japan and Australia the allelic frequency ranges between 0.1-0.18 in controls, and between 0.24-0.52 in AD patients. In the present study on Polish population, we analyzed the frequency of APOE-epsilon 4 allele in persons with Alzheimer's disease (AD). APOE genotypes were determined in 30 mild to moderate AD (83%) and mixed dementia (MIX, 17%), as well as in 11 nondemented first-degree relatives of AD (NDR), recruited from AD patient registry in Warsaw. Among the AD and MIX patients the APOE-epsilon 4, epsilon 3, epsilon 2 allele frequency was 0.333, 0.65 and 0.017 respectively.
2006
Apolipoprotein E (APOE) gene on chromosome 19q13.2 is encoded by three common alleles designated as ε2, ε3 and ε4. In Alzheimer's disease (AD) the ε4 allele is overrepresented and is considered to be a major genetic risk factor. Several methods have been developed to determine APOE genotypes. Among them, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) appears to be highly reliable. In this study, we improved the nonisotopic PCR-SSCP method for determining APOE genotypes in 42 cases of AD patients, 40 cases of non-AD dementia patients, and 49 cases of age-matched controls. DNA from the target sequence on APOE was amplified by PCR from peripheral blood genomic DNA. PCR products were electrophoresed in a non-denaturing polyacrylamide gel and visualized by silver staining. We found that the ε4 allele had a significantly high frequency of occurrence in AD patients (33.3%) compared with age-matched controls (13.3%) (χ 2 = 10.43, p = 0.001) and non-AD dementia (10%) (χ 2 = 13.02, p<0.001) whereas the ε3 allele was of high frequency in non-AD dementia (90%) compared with age-matched controls (85.7%) and AD patients (66.7%). APOE ε4 homozygotes were found only in AD groups. On the other hand, the ε2 allele was found only in an age-matched control. This study confirmed that the APOE ε4 allele is a risk factor in Thai AD subjects and that the PCR-SSCP method is a rapid and useful means of detecting the APOE genotype in AD.
Apolipoprotein E Gene Polymorphism in Alzheimer Patients in Northwest of Iran
Background and Aims: Alzheimer's disease (AD), the most common form of dementia among the elderly, is a progressive, degenerative disorder of the brain with a loss of memory, behavior and cognition. The APOE4 allele is the only established risk factor in the development of AD. However, as the APOE4 allele is neither necessary nor sufficient for the development of AD, this emphasizes the involvement of other genetic and/or environmental factors, which alone or in combination with APOE4 can modify the risk of AD. Methods: EDTA blood from 30 AD and 30 controls were collected and DNA was extracted. The gene was amplified with RFLP-PCR and alleles frequencies for APOE of them were performed. Then results compared between AD case and control subjects by χ 2 test. Results: The frequencies of the APOE2, APOE3 and APOE4 alleles in total population were 0.075, 0.80 and 0.125 respectively (χ 2 = 4.018, P>0.05). A highly significant association was observed between the APOE4 and AD in this population. Conclusion: It seems that The APOE4 frequency in AD patients (18.33%) was about three times higher than in our normal population (8.33%). We suggest detect of APOE genotype for prediction of Alzheimer's disease.
Association analysis of ApoE gene polymorphisms among Egyptian patients with Alzheimer's disease
Gene Reports, 2018
BACKGROUND: Alzheimer disease (AD) is one of the leading causes of dementia among elderly. It is a progressive brain disorder associated with unusual behaviors, personality changes, and irreversible decline in thinking ability. Epsilon 4 allele of apolipoprotein E (ApoE) is considered as a major risk factor for AD in several populations. AIM: we investigated APOE polymorphisms in a group of Egyptian patients with Alzheimer's disease. SUBJECTS AND METHODS: We analyzed APOE polymorphisms in 53 Alzheimer patients who were 60 years or older and the study included a control group of 100 individuals. For APOE genotyping, we used conventional PCRs followed by Restriction Fragment Length Polymorphism (RFLP) analysis. Additionally, we performed Real time PCR analysis to confirm the results of RFLP and apply a more accurate method that is fast, simple, and cost-effective. RESULTS: We observed that E4 allele was associated with 28.3 % of Alzheimer patients as E3/E4 genotype (22.6%) and E4/E4 (17.0%), while we detected it in only 4% of the control group as E3/E4 genotype (8%). E3 allele has been shown in 69.8 % of Alzheimer patients and in 93.5% of the control subjects. We have detected E2 allele in 18.9% of the cases and in 25% of the control group. RT-PCR analysis showed the exact patterns of genotype as determined by RFLP. CONCLUSION: There is a significant association between ApoE4 isomer and Alzheimer dementia in the Egyptian patients.We recommend conducting further studies to screen larger number of patients and confirm that ApoE4 could be considered as a reliable molecular marker for late onset Alzheimer disease (LOAD) among Egyptian elderly.