[Association between angiotensin-converting enzyme gene polymorphism and Alzheimer's disease].

OBJECTIVE: To determine the association between the polymorphism of angiotensin converting enzyme (ACE) gene and Alzheimer's disease (AD). METHODS: This case-control study involved 201 AD patients and 257 healthy subjects matched for age and gender as the control group. Polymerase chain reaction amplification and matrix-assisted laser desorption/ ionization time of flight mass spectrometry were used to examine the rs4291, rs4309, and rs4343 of ACE gene, and the difference in genotypes, allelotype frequencies and haplotype frequencies were analyzed between the two groups. RESULTS: No statistic difference was found in the genotype and allelotype frequencies of rs4291 locus between AD and control groups (P>0.05). A significant difference was found in the genotype and allelotype frequencies of rs4309 between the two groups with a significant increase in the C allelotype frequency in AD group (OR=1.917, 95% CI=1.431-2.568, P<0.05). The difference in the genotype frequency of rs4343 was not significant between the two groups, but the allelotype frequencies differed significantly with a decreased A allelotype frequency in AD group(OR=0.714, 95% CI=0.532-0.957, P=0.024). Analysis of the linkage disequilibrium among the loci of rs4291, rs4309 and rs4343 showed a D' all above 0.65 between one another. Haplotype analysis confirmed the existence of 5 haplotypes, namely ATA, ACA, TCA, TCG and TTG, indicating a negative correlation between haplotype ATA and AD occurrence (OR=0.558, 95% CI=0.420-0.741, P<0.05) and positive correlations of haplotype ACA and TCA with AD occurrence (ACA: OR=4.883, 95% CI=2.267-10.518, P<0.05; TCA: OR=2.269, 95% CI=1.083-4.754, P<0.05). CONCLUSION: The polymorphism of rs4291 may have no relation with the incidence of AD. Polymorphisms of s4309 and rs4343 may be related to AD, and ATA, ACA and TCA haplotypes composed of rs4291/rs4309/rs4343 may be related to AD.

Relationship between Adiponectin Gene Polymorphisms and Late-Onset Alzheimer's Disease.

In recent years, researchers have found that adiponectin (ANP) plays an important role in the pathogenesis of Alzheimer's disease (AD), and low serum concentrations of ANP are associated with AD. Higher plasma ANP level have a protective effect against the development of cognitive decline, suggesting that ANP may affect AD onset. Meanwhile, accumulating evidence supports the crucial role of ANP in the pathogenesis of AD. To study the relationship between ANP gene polymorphisms (rs266729, -11377C>G and rs1501299, G276T) and late-onset AD (LOAD), we carried out a case-control study that included 201 LOAD patients and 257 healthy control subjects. Statistically significant differences were detected in the genotype and allelotype frequency distributions of rs266729 and rs1501299 between the LOAD group and the control group, with a noticeable increase in the G and T allelotype frequency distributions in the LOAD group (P < 0.05). Logistic regression analysis using recessive model and additive model revealed that the rs266729 GG and rs1501299 TT genotypes are associated with a greater risk of LOAD. Haplotype analysis identified four haplotypes: CG, CT, GG, and GT. The frequencies of the CT and GG haplotypes were not significantly different (P > 0.05) between the LOAD group and control group, whereas the CG and GT haplotypes were significantly different (P < 0.05), suggesting a negative correlation between the CG haplotype and LOAD onset (OR = 0.74, 95% CI = 0.57-0.96, P = 0.022), and a positive correlation between the GT haplotype and LOAD onset (OR = 2.29, 95% CI = 1.42-3.68, P = 0.005). Therefore, we speculated that the rs266729 and rs1501299 of ANP gene polymorphisms and the GT and CG haplotypes were associated with LOAD.

Relationship between the gene polymorphisms of kallikrein-kinin system and Alzheimer's disease in a Hunan Han Chinese population.

This study aimed to determine the connection between polymorphisms of kallikrein kinin system including KLK1 (rs5516), KNG1 (rs710446, rs2304456) and ACE (rs4291, rs4309, rs4343) and late-onset Alzheimer's disease (LOAD). The research was conducted as a case-control study, comprising 201 AD patients in the AD group, and 257 healthy subjects as the control group. PCR amplification and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to detect the six polymorphisms (rs5516 in KLK1; rs710446, rs2304456 in KNG1; rs4291, rs4309, rs4343 in ACE) from both groups. No statistically significant difference was found between the genotype and allelotype distributions of rs5516, rs710446, rs2304456, rs4291 and rs4343 (P>0.05). The differences between the genotype and allelotype distributions of the rs4309 were statistically significant (P<0.05). Haplotype analysis confirmed the existence of three haplotypes (AG, AT, GT) composed of rs710446/rs2304456, and six haplotypes (ATA, ACA, TCA, TCG, TTA, TTG) composed of rs4291/rs4309/rs4343, among which the distribution of ATA, ACA, TCA between the two groups was statistically significant difference (P<0.05). Our study showed that the polymorphisms of rs5516, rs710446, rs2304456, rs4291 and rs4343 is not related to the incidence of LOAD. The polymorphisms of rs4309 may be related to LOAD, as well as ATA, ACA, and TCA haplotype composed of rs4291/rs4309/rs4343.

SORL1 gene polymorphism association with late-onset Alzheimer's disease.

We examined the relationship between loci polymorphisms (rs689021, rs3824966, and rs1784933) of the sortilin-related receptor 1 gene (SORL1) and late-onset Alzheimer's disease (LOAD) in the Chinese Han population of the Hunan Changsha region. A case-control association analysis was used. Clinical data and peripheral blood were collected from 201 Alzheimer's disease patients and 257 healthy controls. PCR and MALDI-TOF mass spectrometry detection technologies were used to identify single nucleotide polymorphism (SNP) distribution at SORL1 gene loci. Genotype and allele frequency differences were analyzed and compared between groups. No significant differences were found in genotype frequency distributions of the rs689021 and rs3824966 loci. Similarly, allele frequency distributions of the C and T alleles of rs689021, and the C and G alleles of rs3824966 showed no significant differences. However, the genotype frequency distribution of the rs1784933 locus was significantly different, and the allele frequency distribution of the A and G alleles were also significantly different. Multifactor logistic regression analysis showed that after correcting for confounding factors such as gender, age, and cholesterol, LOAD risk in rs1784933 AA genotype carriers was 1.803 times that in AG+GG genotype carriers. SORL1 gene SNPs at rs689021 and rs3824966 loci show no relationship with LOAD onset in the Chinese Han population of the Hunan Changsha region. Conversely, a SORL1 gene SNP at the rs1784933 locus is associated with LOAD onset, with the A allele being a risk factor.