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Neprilysin has been reported to be a major beta-amyloid peptide (A[beta])-degrading enzyme. The decreased expression and activity of it may contribute to the development of Alzheimer's disease by promoting the accumulation of A[beta]. We used denaturing high-performance liquid chromatography to screen the neprilysin gene (NEP) for single nucleotide polymorphisms (SNPs) in 257 Chinese sporadic Alzheimer's disease patients and 242 cognitive normal controls. As a result, eight novel and one known SNP were identified. Three of them, -204G [right arrow] C in the promoter region, IVS17-294C [right arrow] T, and IVS22+36C [right arrow] A showed a significant association with Alzheimer's disease (p = .006, .017, and .003, respectively). Subsequent haplotype analysis provided further evidence of the association (global p < .0001 for the three SNPs mentioned above, and global p < .01 for the eight SNPs with rare allele frequency >1%). These findings indicate that genetic variations within or extremely close to NEP might influence the susceptibility to Alzheimer's disease in Chinese persons.

Introduction There is a dearth of literature on the incidence of dementia in China. Methods Using a stratified, multistage, cluster-sampling method, 16,921 nondemented participants ≥55 years were recruited from four regional centers in China in 1997 and followed up to 4.5 years. Cases were identified through a three-step protocol, according to standardized criteria for dementia, Alzheimer's dementia (AD), and vascular dementia (VaD). Results The crude incidence in persons ≥65 years was 12.1/1000 person-years for dementia, 8.2/1000 person-years for AD, and 3.1/1000 person-years for VaD. After adjusting for sociodemographic factors, older age and lower education were associated with a higher risk of incident dementia, AD and VaD; regional difference was associated mainly with incidence of VaD (north vs. south: hazard ratio [HR] = 3.59); modestly with AD (east vs. west: HR = 1.55). Discussion The incidence of dementia in Chinese population is comparable with that in Europe and United States. [ABSTRACT FROM AUTHOR]

Introduction: There is a dearth of literature on the incidence of dementia in China., Methods: Using a stratified, multistage, cluster-sampling method, 16,921 nondemented participants ≥55 years were recruited from four regional centers in China in 1997 and followed up to 4.5 years. Cases were identified through a three-step protocol, according to standardized criteria for dementia, Alzheimer's dementia (AD), and vascular dementia (VaD)., Results: The crude incidence in persons ≥65 years was 12.1/1000 person-years for dementia, 8.2/1000 person-years for AD, and 3.1/1000 person-years for VaD. After adjusting for sociodemographic factors, older age and lower education were associated with a higher risk of incident dementia, AD and VaD; regional difference was associated mainly with incidence of VaD (north vs. south: hazard ratio [HR] = 3.59); modestly with AD (east vs. west: HR = 1.55)., Discussion: The incidence of dementia in Chinese population is comparable with that in Europe and United States., (Copyright © 2016 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)

Objective: Alpha-2 macroglobulin (alpha2M) is a proteinase inhibitor found in association with senile plaques in Alzheimer's disease (AD). Also alpha2M has been implicated in several pathophysiological processes in AD. In view of the recent contradictory reports on the relationship between AD and a common polymorphism I1000V in A2M gene, the present authors studied a relatively large sample, determined the genotype of the I1000V polymorphism in A2M gene in sporadic AD patients and age-matched controls with normal cognition, and examined the possible association of the polymorphism with AD., Methods: Genotypes of A2M and apolipoprotein E (apoE) were detected by polymerase chain reaction combined with restriction fragment length polymorphism in 257 patients and 242 controls in Guangzhou, and 112 patients and 113 controls in Chengdu., Results: The 1000Val allele frequencies in the merged AD and control groups were 7.7% and 8.7%, respectively. The differences of allelic and genotypic frequencies between the patients and control subjects were not statistically significant, even after stratification by apoE epsilon4 status or by age-of-onset of the disease., Conclusion: The results of this study revealed no association between the I1000V polymorphism of A2M and Chinese sporadic AD in Guangzhou and Chengdu.

Beta-site amyloid-precursor protein cleaving enzyme (BACE1) is a candidate risk factor for Alzheimer's disease (AD) because of involving in generating beta-amyloid peptide, which is thought to play a central role in the pathogenesis of the disease. A single nucleotide polymorphism 1239G/C in exon 5 of BACE1 gene and a weak association between this polymorphism and AD in Caucasian APOEepsilon4 allele carriers has been reported. To examine possible association of the polymorphism with sporadic AD, two Chinese Han cohorts including 257 patients and 242 age-matched controls in Guangzhou and 112 patients and 113 controls in Chengdu were genotyped using PCR-RFLP techniques. The frequency of the C allele in controls of both cohorts was 0.65, which was higher than that in Caucasian populations [0.39 by Nowotny et al. 2001: Neuroport 12:1799-1802; 0.44 by Nicolaou et al. 2001: Neurogenetics 3:203-206]. There was a significant excess of C allele among the patients in both cohorts (Guangzhou, 0.71 vs. 0.65, chi(2) = 5.20, P = 0.02; Chengdu, 0.74 vs. 0.65, chi(2) = 4.36, P = 0.04). The CC genotype was found to be associated with AD (Guangzhou cohort, OR = 1.56, 95% CI = 1.09-2.23; Chengdu cohort, OR = 1.74, 95% CI = 1.03-2.95; combined sample: OR = 1.61, 95% CI = 1.20-2.17). The association remained in non-APOE epsilon4 allele carriers when all subjects were divided on the basis of the APOEepsilon4 status. Our findings suggest that the 1239G/C polymorphism in exon 5 of BACE1 gene may be associated with sporadic AD in Chinese Hans., (Copyright 2003 Wiley-Liss, Inc.)