Single nucleotide polymorphism rs1333049 on chromosome 9p21.3 is associated with Alzheimer's disease in Han Chinese

BackgroundChromosome 9p21.3 polymorphism has been shown to affect susceptibility to Alzheimer's disease (AD) in Caucasians, while there are no studies on the association of chromosome 9p21.3 polymorphism with the risk of AD in Asians.MethodsThe study investigated 266 sporadic late-onset AD (LOAD) and 323 healthy controls matched for sex and age in a Han Chinese population. The common genetic variant (tagged by rs1333049, G/C) on chromosome 9p21.3 was genotyped using MALDI-TOF mass spectrometry.ResultsPatients with LOAD had higher frequencies of C allele (56.0% vs. 49.2%) compared with controls [odds ratio (OR) 1.31, 95% confidence interval (CI) 1.04–1.65, P = 0.02]. After stratification by APOE ε4-carrying status, the C allele of rs1333049 was only significantly associated with LOAD in non-APOE ε4 allele carriers (OR 1.47, 95% CI 1.09–1.98, P < 0.01). rs1333049 polymorphism was still strongly associated with LOAD [dominant model: OR 1.83, 95% CI 1.17–2.86, P < 0.01; additive model: OR 1.38, 95% CI 1.05–1.80, P = 0.02] after adjusting for the APOE ε4 carrier status and other vascular risk factors.ConclusionsThis study demonstrates an association of rs1333049 polymorphism locus on chromosome 9p21.3 with risk for LOAD in Han Chinese.     

Genetic association of rs11610206 SNP on chromosome 12q13 with late-onset Alzheimer's disease in a Han Chinese population

BackgroundSeveral genome wide screens and candidate gene studies have implicated the chromosome 12p13 locus as possibly harboring genetic variants predisposed to late-onset Alzheimer's disease (LOAD). Recently, the strongest significant association was reported for the single nucleotide polymorphism (SNP) rs11610206 on chromosome 12q13 in an independent genome-wide association study (GWAS) in Caucasians.MethodsWe investigated whether the SNP on chromosome 12q13 was associated with LOAD in a Han Chinese population. The common rs11610206 SNP on chromosome 12q13 was genotyped using MALDI-TOF mass spectrometry in 322 patients with LOAD and in 391 healthy controls matched for sex and age.ResultsPatients with LOAD had higher frequencies of T allele (56.0% versus 49.2%) compared with controls [odds ratio (OR) = 1.45, 95% confidence intervals (CI) = 1.08–1.95, and P = 0.01]. After stratification by APOE ε4-carrying status, the T allele of rs11610206 was significantly associated with LOAD only in APOE ε4 allele carriers (OR = 2.05, 95% CI = 1.21–3.47, and P = 0.007). Furthermore, multivariate logistic regression analysis showed that the TT genotype carriers demonstrated a 1.52-fold risk when compared with (TC + CC) genotype carriers (OR = 1.52, 95% CI = 1.07–2.17, and P = 0.02).ConclusionsThis study demonstrates an association of rs11610206 polymorphism locus on chromosome 12q13 with risk for LOAD in Han Chinese.     

A single nucleotide polymorphism in LRP2 is associated with susceptibility to Alzheimer's disease in the Chinese population

BackgroundLRP2 (also called megalin) plays a potential key role in the pathogenesis of Alzheimer's disease (AD). Recently, one genome-wide association study has revealed that the rs3755166 (G/A) polymorphism located in the LRP2 promoter is associated with development of AD in Caucasians, while there are no studies on the association LRP2 of with AD risk in Asians.MethodsTo evaluate the relationship between the rs3755166 polymorphism of the LRP2 gene and AD in the ethnic Chinese Han, we conducted a case-control study (n = 361, age > 50) to determine the prevalence of one common single-nucleotide polymorphism (SNP) of LRP2 (rs3755166) in patients with AD in Chinese population of Mainland China, and clarified whether this polymorphism is a risk factor for AD.ResultsThe prevalence of the minor allele (A) in the rs3755166 polymorphism was significantly different in AD patients and control subjects (P < 0.05). The rs3755166 polymorphism was associated with AD in the ethnic Chinese Han (OR = 1.378, 95% CI: 1.017-1.867, P = 0.039), and the results were not influenced by age, gender, or APOE status (P = 0.441, P = 0.94, P = 0.432, respectively).ConclusionOur data revealed the allele (A) of the rs3755166 polymorphism within LRP2 gene may contribute to AD risk in the Chinese Han Population.     

IL-16 rs11556218 gene polymorphism is associated with coronary artery disease in the Chinese Han population

Objective

Our aim was to investigate the association between IL-16 gene polymorphisms (rs4778889 C/T and rs11556218 G/T) and coronary artery disease (CAD).

Design and methods

The initial cohort consisted of 300 CAD patients and 397 controls from the Chinese Han population. Genotyping was performed by using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). The positive association between polymorphism and CAD was replicated in another independent cohort, which included 424 CAD cases and 332 controls.

Results

In the initial study, the allele and genotype frequencies of rs4778889 were not different between in CAD and controls (P > 0.05). However, The G allele frequency of rs11556218 was significantly higher in the CAD cases than in the controls (CAD, 46.8% vs. controls, 22.8%, P < 0.001). The risk of CAD was significantly higher in the G allele carriers than in the non-carriers (P < 0.001, adjusted odds ratio = 7.27; 95% confidence interval, 4.13–12.8). In the replication cohort, G carriers of rs11556218 also had a higher risk of CAD (P = 0.005, adjusted OR = 2.33; 95% confidence interval, 1.45–3.74).

Conclusion

Our study suggested that IL-16 rs11556218 G/T polymorphism is significantly associated with the risk of CAD in the Chinese Han population.     

Genetic variant in visfatin gene promoter is associated with decreased risk of coronary artery disease in a Chinese population

BackgroundVisfatin is a newly identified pro-inflammatory adipokine expressed predominantly in visceral fat. Previous studies have suggested a role for visfatin in low-grade inflammation and regulation of lipid metabolism. Most recently, a genetic polymorphism ? 1535C > T located in the visfatin gene promoter has been identified, and suggested to be associated with the regulation of visfatin expression, lipid levels. However, it is unclear whether this polymorphism has a linkage with CAD.MethodsWe conducted a hospital-based case-control study with 257 CAD patients and 292 controls to examine the potential association of the Visfatin ? 1535C > T polymorphism with CAD.ResultsThe frequencies of the CC, CT, and TT genotypes in cases were significantly different from those of controls (χ² = 6.223, P = 0.045). Subjects with the variant genotypes (CT + TT) had a 40% decreased risk of CAD relative to CC carriers (adjusted OR = 0.60, 95%CI = 0.40–0.89). Furthermore, the adjusted OR of a TT genotype for CAD was 0.52 (95%CI = 0.31–0.87). There was a significant association between Visfatin ? 1535C > T polymorphism and triglyceride levels in both CAD patients and controls (P = 0.003, 0.018, respectively). In stratified analyses, the T allele was significantly associated with reduced risk of CAD in males, subjects with age < 59 years, and non-smokers. Moreover, a borderline statistical significance (P = 0.058 for trend) was observed between the variant genotypes and severity of CAD.ConclusionOur results suggested that Visfatin ? 1535C > T polymorphism might be associated with reduced risk of CAD in a Chinese population.     

ABCG1基因启动子区多态性与中国南方汉族人群冠心病多支血管病变的相关性

目的：探讨中国南方汉族人群三磷酸腺苷结合盒转运体G1（ ATP binding cassette transporter G1, ABCG1）基因启动子区单核苷酸多态性与冠心病（ coronary artery disease , CAD）的相关性。方法采用病例对照研究,采用单碱基引物延伸的多重PCR法检测482例冠状动脉造影证实的CAD患者和513例对照者的ABCG1基因启动子区域rs1378577位点A／C多态性,分析该位点多态性与中国南方汉族人群CAD易感性和病变血管数的关系。结果 rs1378577 A／C等位基因和基因型频率在CAD组和对照组之间的分布比较差异无统计学意义（ P＞0.05）;校正了性别、年龄、吸烟状况、高血压、高脂血症、糖尿病等危险因素后, rs1378577 A／C基因多态性与CAD无相关性（ P＞0.05）;rs1378577 A／C多态性在CAD单支病变和多支病变之间的分布比较差异无统计学意义（ P＞0.05）;逻辑回归分析显示,以AA vs AC＋CC分析时rs1378577 A／C多态性可能与冠状动脉病变血管数相关（OR 0.724,95％CI 0.526～0.995,P＝0.047）。结论 ABCG1基因启动子区rs1378577位点A／C多态性可能与中国南方汉族人群冠心病多支血管病变相关。     

Naming impairment in Alzheimer's disease is associated with left anterior temporal lobe atrophy

There is considerable debate about the neuroanatomic localization of semantic memory, the knowledge of culturally shared elements such as objects, concepts, and people. Two recent meta-analyses of functional imaging studies (fMRI and PET) sought to identify cortical regions involved in semantic processing. Binder and colleagues (Binder et al., 2009) identified several regions of interest, widely distributed throughout the frontal, parietal, and temporal cortices. In contrast, Lambon Ralph and colleagues (2010) focused on the anterior temporal lobe, and found that when the potential for signal loss is accounted for (due, for example, to distortion artifact or field of view restriction), significant regional activation is detected. We set out to determine whether the anterior temporal lobe plays a significant role in picture naming, a task which relies on semantic memory. We examined a relatively large sample of patients with early Alzheimer's disease (N=145), a multifocal disease process typically characterized in the early stages by problems with episodic memory and executive function. Hypothesis-driven analyses based on regions of interest derived from the meta-analyses as well as exploratory analyses across the entire cerebral cortex demonstrated a highly specific correlation between cortical thinning of the left anterior temporal lobe and impaired naming performance. These findings lend further support to theories that include a prominent role for the anterior temporal lobe in tasks that rely on semantic memory.     

APOE4 is associated with greater atrophy of the hippocampal formation in Alzheimer's disease

Prior studies reported that the hippocampal volume is smaller in Alzheimer's disease patients carrying the Apolipoprotein E ε4 allele (APOE4) versus patients who are non-carriers of this allele. This effect however has not been detected consistently, possibly because of the regionally-specific involvement of the hippocampal formation in Alzheimer's disease. The aim of this study was to analyze the local effect of APOE4 on hippocampal atrophy in Alzheimer's disease patients. Using high-resolution T1-weighted images we investigated 14 patients heterozygous for the ε4 allele (age 72±8 SD years; MMSE 20±4 SD) and 14 patients not carrying the ε4 allele (age 71±10; MMSE 20±5 SD), and 28 age-, sex-, and education-matched controls (age 71±8; MMSE 29±1 SD). The hippocampal formation was outlined with manual tracing and 3D parametric surface models were created for each subject. Radial atrophy was assessed on the whole hippocampal surface using the UCLA mapping technique. E4 carriers and non-carriers did not differ in their level of impairment in global cognition (p=0.91, Mann-Whitney test) or memory (p>0.29). Hippocampal surface analysis showed the typical pattern of CA1 and subicular tissue atrophy in both ε4-carriers and non-carriers compared with controls (e4 carriers: p<0.0002; ε4 non-carriers: p<0.01, permutation test). The left hippocampal volume was significantly smaller in ε4-carriers than non-carriers (p=0.044, Mann-Whitney test), the effect of APOE4 mapping to the subicular/CA1 region (p=0.041, permutation test). Differences were not statistically significant in the right hippocampus (p>0.20, permutation test). These findings show that hippocampal atrophy is greater in APOE4 carriers in regions typically affected by pathology. APOE4 may affect the structural expression of Alzheimer's disease.     

Thrombospondin-4 A387P polymorphism is not associated with coronary artery disease and myocardial infarction in the Chinese Han population

Recently, conflicting data have been reported regarding the possible contribution of the TSP-4 (thrombospondin-4) A387P polymorphism to CAD (coronary artery disease) or MI (myocardial infarction). To investigate a possible association between the A387P polymorphism and CAD or MI in the Chinese Han population, we conducted a case-controlled study including 817 patients with angiographically verified CAD or those who survived an acute MI and 847 control subjects. The TSP-4 A387P polymorphism was determined by PCR and PCR-RFLP (restriction-fragment-length polymorphism) analysis. The prevalence of the 387P allele was 3.8% in the healthy controls, which was less frequent than those in Western populations (19.6-23.2%). No association of the A387P polymorphism with an altered risk of CAD, MI or premature MI was found in our present study (CG+CC compared with GG, P (CAD)=0.51, P (MI)=0.13, P (Premature MI)=0.17 respectively). We concluded that a relationship between the TSP-4 A387P polymorphism and CAD or MI was unlikely in our population. Additional investigations should be performed in populations at different risk of coronary events in order to elucidate further the possible contribution of this polymorphism to cardiovascular disease.     

Novel mutations of mitochondrial DNA associated with type 2 diabetes in Chinese Han population

Mitochondrial single nucleotide polymorphisms (mtSNPs) have been reported to associate with type-2 diabetes mellitus (T2DM), but mtSNPs appear to be considerably different among different populations and regions. To determine mtSNPs in Chinese Han patients with T2DM, the entire sequences of the mitochondrial genomes from 72 T2DM Chinese (59 +/- 4 years) and 50 age-matched healthy subjects (controls) in Chongqing region of Western China were directly sequenced and mtSNPs were analyzed. We found that M8, M9, D, G, R and A haplogroups exist in Chinese Han population and the frequency of haplogroup M9 was significantly higher in patients with T2DM than in the controls (p = 0.0006, OR 0.06 [95% CI 0.008-0.476]). MtSNPs T3394C in NADH dehydrogenase subunit 1 (ND1), G4491A in ND2, T16189C and T16519C were found with significantly higher frequency in patients with T2DM than in the controls (T16189C, p = 0.0045; T16519C, p < 0.0001; T3394C, p = 0.0015; G4491A, p = 0.0015). In contrast, the frequency of C5178A in ND2 and A10398G in ND3 was higher in the controls than in patients with T2DM (C5178A, p = 0.014; A10398G, p = 0.0011). Our results indicate that mtSNPs T3394C, G4491A, T16189C and T16519C show susceptible tendency to T2DM and mtSNPs C5178A and A10398G seem to be genetic factors for against T2DM. These mtSNPs determined in our study is useful and could be used for early diagnosis and prevention of T2DM in Chinese Han population.     

Atrophy is associated with posterior cingulate white matter disruption in dementia with Lewy bodies and Alzheimer's disease

Hippocampal atrophy and posterior cingulate hypometabolism are common features of both Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). These regions show correlated activity at rest as part of the 'default network', and they are connected by the cingulum, a white matter (WM) tract. We hypothesised that hippocampal atrophy would be associated with disruption of the cingulum, as determined by diffusion tensor imaging. We recruited 15 people with AD, 16 with DLB, and 15 healthy control subjects of similar age. They were scanned on a 1.5 T MRI system with a T1 weighted 3D sequence and diffusion tensor FLAIR imaging. The T1 images were segmented into grey and white matter and spatially normalised using SPM. Hippocampal atrophy was estimated by calculating the mean grey matter (GM) volume from a region of interest in standard space and global atrophy from the total CSF segmentation. Fractional anisotropy (FA) maps were calculated and also spatially normalised. Using SPM, a multivariate correlation of FA against hippocampal GM, global atrophy and disease group was performed. We found a bilateral region adjacent to the posterior cingulate and encompassing a branch of the cingulum where global atrophy correlated with fractional anisotropy, after controlling for diagnosis and hippocampal GM. The results suggest that dementia disease progression as measured by global atrophy is associated with disruption of the white matter which connects posterior cingulate and lateral parietal regions. Hence, in addition to the hypometabolism in these regions in AD and DLB, there is also disruption to the white matter connecting them. Future studies are needed to determine whether the disruption precedes or is consequent on atrophy or hypometabolism.     

Apo E genotypes in multiple sclerosis, Parkinson's disease, schwannomas and late-onset Alzheimer's disease

Apolipoprotein E (apo E) exists in there allelic, functionally distinct isoforms (apo E2, E3 and E4). Recent work has suggested that apo-E-dependent uptake of lipoproteins may play important roles in the development and maintenance of the nervous system and in the responses to both peripheral and central nervous system injury. If apo-E-mediated transport of lipids were a rate-limiting step in these processes, one might expect that the functional differences between the alleles would be associated with varying predispositions to neurodegenerative and demyelinating diseases. Thus, we looked for an association between particular apo E genotypes and susceptibility to multiple sclerosis and Parkinson's disease. If apo-E-mediated cholesterol uptake were limiting in neuronal growth, one might also expect that apo E2 alleles would slow CNS tumour growth. Accordingly, apo E genotypes were investigated in individuals with sporadic vestibular schwannomas and neurofibromatosis type 2 (NF-2). No significant alteration in the apo E allele distributions was observed in any of these conditions, nor did the apo E genotypes correlate with disease severity. However, we confirmed the previous findings of an over-representation of tha apo E4 allele in autopsy-diagnosed late-onset Alzheimer's disease patients. In addition, our data supported the recent observations that apo E2 may be associated with a protective effect for late-onset Alzheimer's disease. These contrasting risks associated with the apo E2 and E4 alleles strengthen the suggestions that this gene is directly involved in the pathogenesis of Alzheimer's disease.     

The T-1237C polymorphism of the Toll-like receptor-9 gene is associated with chronic kidney disease in a Han Chinese population

Chronic kidney disease (CKD) is increasingly recognized as a global public health problem. As inflammatory processes and genetic factors are involved in the pathogenesis of CKD, we have investigated the potential genetic contribution of Toll-like receptor (TLR) gene polymorphisms in CKD. In a case-control association study, 149 CKD patients and 429 healthy controls were genotyped by real-time polymerase chain reaction. CKD patients were defined as kidney damage (albuminuria, proteinuria or hematuria) or glomerular filtration rate < 60 ml/min/1.73 m(2) for 3 months or more. Single nucleotide polymorphisms (SNPs) at TLR-2 G2408A, TLR-4 A12874G and C13174T, and TLR-9 T-1237C, T-1486C, and G1635A were assessed, and linkage disequilibrium calculations and haplotype association analysis were undertaken. The functions of TLR-9 have been documented to recognize the viral and bacterial CpG DNA sequences, whereas detects microbe-derived peptidoglycan and lipopeptides and TLR-4 binds lipopolysaccharides. SNPs within the TLR genes may influence promoter activity, mRNA conformation and subcellular localization, and/or protein structure and function. Our results show that only the TLR-9 T-1237C and G1635A gene polymorphisms demonstrate an association with CKD (p = 0.002 and p = 0.04, respectively). The TLR-9 TCA haplotype at T-1237C, T-1486C, and G1635A was associated with a lower risk of CKD, whereas the TTA haplotype was associated with a higher risk of CKD. In the Han Chinese population, those who carry the C and A alleles at SNPs T-1237C and G1635A in the TLR-9 gene appear to be more susceptible to the development of CKD.     

Ser1369Ala variant in sulfonylurea receptor gene ABCC8 is associated with antidiabetic efficacy of gliclazide in Chinese type 2 diabetic patients

OBJECTIVE—The purpose of this study was to investigate whether genetic variants could influence the antidiabetic efficacy of gliclazide in type 2 diabetic patients.RESEARCH DESIGN AND METHODS—A total of 1,268 type 2 diabetic patients whose diabetes was diagnosed within the past 5 years and who had no recent hypoglycemic treatment were enrolled from 23 hospitals in China. All of the patients were treated with gliclazide for 8 weeks. Fasting and oral glucose tolerance test 2-h plasma glucose, fasting insulin, and A1C were measured at baseline and after 8 weeks of treatment. We used two independent cohorts to test the associations of 25 single nuclear polymorphisms in 11 candidate genes with the antidiabetic efficacy of gliclazide. A general linear regression model was used to test the association with adjustment for important covariates.RESULTS—After 8 weeks of gliclazide therapy, mean fasting plasma glucose (FPG) was reduced from 11.1 mmol/l at baseline to 7.7 mmol/l. In cohort 1, we genotyped all 25 SNPs (n = 661) and found that Ser1369Ala of the ABCC8 gene and rs5210 of the KCNJ11 gene were significantly associated with decreases in FPG (P = 0.002). We further genotyped Ser1369Ala in cohort 2 (n = 607) and confirmed the association identified in cohort 1. In the pooled analysis, compared with subjects with the Ser/Ser genotype, subjects with the Ala/Ala genotype had a 7.7% greater decrease in FPG (P < 0.001), an 11.9% greater decrease in 2-h plasma glucose (P = 0.003), and a 3.5% greater decrease in A1C (P = 0.06) after 8 weeks of treatment with gliclazide.CONCLUSIONS—In two independent cohorts of Chinese type 2 diabetic patients, we found consistent evidence that the Ser1369Ala variant in the ABCC8 gene can influence the antidiabetic efficacy of gliclazide.The epidemic of type 2 diabetes in the last decade in both developed and developing countries has made it a major threat to global public health. At least 171 million people worldwide had diabetes in 2000, and this figure is likely to more than double by 2030 to reach 366 million (1). The majority of diabetes is type 2 diabetes. Most of the recent rise in diabetes prevalence is probably a result of lifestyle and dietary changes, but there is also clear evidence for genetic predisposition to this complex disease. During the last decade, molecular genetic studies of type 2 diabetes have shown significant progress (2). Five genome-wide association studies have been published since February 2007, increasing the number of confirmed type 2 diabetes susceptibility loci from three (PPARG, KCNJ11, and TCF7L2) to 9 (with the addition of CDKAL1, CDKN2A/B, IGF2BP2, HHEX/IDE, FTO, and SLC30A8) (2). In addition, studies have lent support for the involvement of many other genes, such as ABCC8 (3–6). In contrast, few studies have investigated whether genetic variants may modulate the response to antidiabetic agents in type 2 diabetic patients (7–9). Such information can assist clinicians in developing individualized treatment plans that will maximize therapeutic efficacy and minimize side effects.Sulfonylurea is a widely used oral hypoglycemic agent. Most type 2 diabetic patients respond well to this agent, but variable efficacy is seen, and primary failure to sulfonylurea treatment is seen in a small portion of patients. Secondary failure of sulfonylurea monotherapy develops in ∼34% of patients at 5 years (10). To explore the underlying genetic factors that may explain individual variable response to sulfonylurea, we conducted a hospital-based pharmacogenetic study. Our goal was to examine whether type 2 diabetes candidate gene variants can influence the antidiabetic efficacy of gliclazide, a commonly used sulfonylurea hypoglycemic agent, in Chinese type 2 diabetic patients.     

Hippocampal degeneration is associated with temporal and limbic gray matter/white matter tissue contrast in Alzheimer's disease

Recent studies have demonstrated alterations in cortical gray to white matter tissue contrast with nondemented aging and in individuals with Alzheimer's disease (AD). However, little information exists about the clinical relevance of such changes. It is possible that changes in MRI tissue contrast occur via independent mechanisms from those traditionally used in the assessment of AD associated degeneration such as hippocampal degeneration measured by more traditional volumetric magnetic resonance imaging (MRI). We created cortical surface models of 95 cognitively healthy individuals and 98 individuals with AD to characterize changes in regional gray and white matter T1-weighted signal intensities in dementia and to evaluate how such measures related to classically described hippocampal and cortical atrophy. We found a reduction in gray matter to white matter tissue contrast throughout portions of medial and lateral temporal cortical regions as well as in anatomically associated regions including the posterior cingulate, precuneus, and medial frontal cortex. Decreases in tissue contrast were associated with hippocampal volume, however, the regional patterns of these associations differed for demented and nondemented individuals. In nondemented controls, lower hippocampal volume was associated with decreased gray/white matter tissue contrast globally across the cortical mantle. In contrast, in individuals with AD, selective associations were found between hippocampal volume and tissue contrast in temporal and limbic tissue. These results demonstrate that there are strong regional changes in neural tissue properties in AD which follow a spatial pattern including regions known to be affected from pathology studies. Such changes are associated with traditional imaging metrics of degeneration and may provide a unique biomarker of the tissue loss that occurs as a result of AD.