中国广西人群中RTN4基因遗传多态性的研究

目的:研究RTN4基因rs2920891A/C和rs17046647A/G位点多态性在广西人群中的分布特征,比较不同人群的分布差异。方法:本实验采用多重单碱基延伸PCR(SNa Pshot)和DNA测序方法,对323例广西健康体检者RTN4基因的rs2920891A/C和rs17046647A/G位点基因型进行检测,并与国际人类基因组单体型图计划(Hap Map)公布的不同人群(北京、日本、欧洲及非洲人群)RTN4基因多态性数据进行比较。结果:在广西人群中,RTN4基因rs2920891A/C位点存在AA、AC、CC基因型及A、C等位基因,其等位基因频率在男女间的分布差异有统计学意义(P0.05),基因型及等位基因频率与日本、欧洲及非洲人群比较差异均有统计学意义(P0.05);rs17046647A/G位点存在AA、AG、GG基因型和A、G等位基因,基因型及等位基因频率在男女间比较差异无统计学意义(P0.05),而与日本、欧洲及非洲人群比较差异均有统计学意义(P0.01)。结论:中国广西人群中RTN4基因的rs2920891A/C和rs17046647A/G位点多态性与其他种族间存在差异性。     

Evaluation of resequencing on number of tag SNPs of 13 atherosclerosis-related genes in Thai population

In the candidate gene approach, information about the distribution of single nucleotide polymorphisms (SNPs) is a crucial requirement for choosing efficient markers necessary for a case-control association study. To obtain such information, we discovered SNPs in 13 genes related to atherosclerosis by resequencing exon-flanking regions of 32 healthy Thai individuals. In total, 194 polymorphisms were identified, 184 of them SNPs, four insertions, and the rest deletions. Fifty-nine of the SNPs were characterized as novel polymorphisms, and these accounted for 30% of the identified SNPs. Comparing allele frequency distributions of the Thai population with other Asian populations shows similar patterns. In contrast, a low correlation pattern (r = 0.521) was found when comparing with either Caucasian or African populations. However, some rare alleles (rs11574541 and rs10874913) are found in the Thai population but not in other Asian populations. Most of the novel SNPs found were located outside the haplotype blocks generated by known SNPs in the Thai population. Only 5.77% of the novel SNPs lies in these defined haplotype blocks. The selection of haplotype-tagging SNPs shows that 8 of 13 genes benefited from the ethnic-specific genotype information. That is, when at least one novel SNP was present, the tagging SNPs chosen were altered. Functional prediction of 16 nonsynonymous SNPs (nsSNPs) by three different algorithm tools demonstrated that five nsSNPs possibly alter their corresponding protein functions. These results provide necessary information for conducting further genetic association studies involving the Thai population and demonstrate that resequencing of candidate genes provides more complete information for full genetic studies. Chintana Tocharoentanaphol and Somying Promso contributed equally to this work.     

No NRG1 V266L in Chinese patients with schizophrenia

NRG1 is one of the best-supported schizophrenia (SZ) susceptibility genes. A NRG1 V266L missense mutation has been found to be associated with SZ in several populations. V266L is not in linkage disequilibrium with any of the SZ-associated NRG1 haplotypes described thus far, and may represent an independent SZ susceptibility locus within NRG1 gene. V266 is a highly conserved residue and its substitution is predicted to have a deleterious effect on the protein. As there are no data for V266L in Chinese, and given the potential relevance of this mutation, we investigated the V266L prevalence in 270 Chinese patients with schizophrenia and 270 ethnically matched controls. V266L was found neither in patients nor in controls. Lack of replication of an association across populations may be because of the differences in linkage disequilibrium structure or allele frequencies. Some true associations may not be replicated regardless of the sample size of the study.     

Association study of neuregulin 1 gene polymorphisms with auditory P300 in schizophrenia

Neuregulin 1 (NRG1), a gene involved with myelin production has been shown to have a positive correlation with schizophrenia. Event-related potentials (ERPs) studies provide the evidence of disturbed electrophysiologic marker in schizophrenia. The present study investigated the association of NRG1 genotypes with P300 in schizophrenia. Three polymorphisms in NRG1 gene were detected in 287 Chinese Han schizophrenics and 120 healthy control subjects. Among the total sample, 140 patients and 96 controls underwent P300. There were no significant differences for genotype distributions and allele frequencies between schizophrenic group and the control. A significant difference was observed between the schizophrenic patients and controls in the AT haplotype, with Odds Ratio 0.304 (P = 0.000882, 95% CI = 0.145-0.636). P300 amplitude in the schizophrenic group was significantly lower than that of the controls at Fz, Cz, Pz. P300 latency in the schizophrenic group was also significantly longer than that of the controls at Cz, Pz, Fz. Significant differences of P300 latency between three genotypes of rs3924999 were found at Cz and Pz both in schizophrenic group and the controls. The G/G carriers of rs3924999 tended to perform worse in the P300 latency as compared to A/A or A/G carriers both in the schizophrenia and controls. There were no significant differences for P300 latency and amplitude between schizophrenic group and controls for AT haplotype. NRG1 gene is a susceptible gene for Chinese Han schizophrenia and AT haplotype might have the protective role in the schizophrenia. Rs3924999 in NRG1 gene might functionally impact cognitive processing.     

Methylenetetrahydrofolate reductase gene polymorphisms and cerebral palsy in Chinese infants

Genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) have been suggested as being associated with cerebral palsy (CP) but the evidence is uncertain. The purpose of this study was to investigate whether MTHFR gene polymorphisms contribute to the development of CP in Chinese infants. For this study, 169 health controls and 159 infants with CP including 43 cases also suffering from mental retardation (MR) were recruited. Genomic DNA was prepared from venous blood and all five single nucleotide polymorphisms in MTHFR (rs4846049, rs1476413, rs1801131, rs1801133 and rs9651118) were genotyped using TaqMan technology. There were no significant differences in allele or genotype frequencies between the CP patients and controls at any of the five genetic polymorphisms. Subgroup analysis found statistically significant difference in allele and genotype frequencies between cases with both CP and MR (CP + MR) compared with both CP-only cases and controls at rs4846049, rs1476413 and rs1801131. The frequencies of the T alleles of rs4846049, rs1476413 and the G allele of rs1801131 were greater in the CP + MR patients than in the CP-only patients and controls. This study provides the first evidence pointing to a MTHFR gene polymorphism as a potential risk factor for CP combined with MR.     

Genetic impact of functional single nucleotide polymorphisms in the 3'-UTR region of the chemoattractant receptor expressed on Th2 cells (CRTH2) gene on asthma and atopy in a Japanese population

BACKGROUND: The human chemoattractant receptor expressed on Th2 cells (CRTH2), the receptor for prostaglandin D2, induces cell migration in eosinophils, basophils, and Th2 cells. The gene encoding CRTH2 is located on chromosome 11q13. Several groups, including ours, have reported significant associations between this region and various traits associated with allergic diseases such as asthma and atopy. Two single nucleotide polymorphisms in the 3'-UTR of the CRTH2 gene (1544G-->C and 1651G-->A) are associated with the mRNA stability of the gene; they have also been associated with asthma in both African American and Chinese populations. METHODS: Because CRTH2 is a biologically important candidate gene on chromosome 11q13, we conducted a case-control analysis using 787 Japanese subjects (384 asthmatics and 403 controls) to evaluate the genetic impact of the CRTH2 gene on asthma and asthma-related traits. Four polymorphisms [1544G-->C (rs11571288), 1651G-->A (rs545659), 11336T-->C (rs2074422), and 12375G-->T (rs561285)] were studied. RESULTS: The allele, genotype, or haplotype frequencies for 2 functional polymorphisms in our Japanese population were significantly different from those in the Chinese or African American populations. No association was found between any polymorphisms or haplotypes in the CRTH2 gene and asthma, atopy, or total serum IgE levels in a Japanese population. CONCLUSIONS: Our data failed to support previous associations of functional polymorphisms at the 3'-UTR of the CRTH2 gene implicated in asthma. We did show a significant difference in the allele and genotype frequencies as well as different haplotype frequencies among African American, Chinese, and Japanese populations, suggesting that the genetic impacts of these functional polymorphisms on asthma and asthma-related phenotypes may vary in different populations.     

Novel thymidylate synthase enhancer region alleles in African populations

Thymidylate synthase (TS) regulates the production of DNA synthesis precursors and is an important target of cancer chemotherapy. A polymorphic tandem repeat sequence in the enhancer region of the TS promoter was previously described, where the triple repeat gives higher in vitro gene expression than a double repeat. We recently identified ethnic differences in allele frequencies between Caucasian and Asian populations. We now describe assessment of genotype and allele frequencies of the TS polymorphism in 640 African (African American, Ghanaian and Kenyan) and Caucasian (UK, USA) subjects. The double and triple repeat were the predominant alleles in all populations studied. The frequency of the triple repeat allele was similar between Kenyan (49%), Ghanaian (56%), African American (52%), American Caucasian (54%) and British Caucasian (54%) subjects. However, two novel alleles contained 4 and 9 copies of the tandem repeat. These novel alleles were found at a higher allele frequency in African populations (Kenyan 7%, Ghanaian 3%, African American 2%) than Caucasians (UK 1%, USA 0%). The novel alleles identified in this study decrease in frequency with Western migration, while the common alleles are relatively stable. This is a unique example suggesting the influence of multiple selection pressures within individual populations. Hum Mutat 16:528, 2000.     

Association of schizophrenia in African Americans to polymorphism in synapsin III gene

Linkage studies in families with schizophrenia have pointed to chromosome 22q12-q13 as one of several regions of the genome that may contain a susceptibility gene. The gene coding for synapsin III, an intrinsic synaptic vesicle membrane protein, maps to this target region. Two tightly linked single-nucleotide polymorphisms were recently found in a small subset of patients with SZ - a synonymous variant, L469L (469G>A), and a non-synonymous variant, S470N (470G>A) - which results in the loss of a mitogen-activated protein kinase serine phosphorylation site. We also found a slight increase in 470A in Caucasian patients from the US with schizophrenia. But, the sample size and allele frequency were too small to draw definitive conclusions. However, both single-nucleotide polymorphisms were much more polymorphic in African American controls than in Caucasian controls, thereby providing a better sample cohort to analyze for schizophrenia involvement. For the codon 469 single-nucleotide polymorphisms, a 50-fold increase was observed in the frequency of 469A in African Americans compared with Caucasians. Furthermore, there was an increase in the percentage of African American patients with schizophrenia who were homozygous for the 469A allele compared with controls who were homozygous (11 versus 5%; AA vs. all other genotypes - Fisher statistic=3.08, P=0.04, one-tailed). An increase in 470A heterozygotes was also found, but the results fell short of being statistically significant. The findings support a role for synapsin III in a subset of African American patients with schizophrenia and raises questions about selective pressure in Africa to account for the extraordinary disparity of the 469 and 470 single-nucleotide polymorphisms in different ethnic populations.     

Association study of polymorphisms in N-methyl-D-aspartate receptor 2B subunits (GRIN2B) gene with Korean alcoholism

The N-methyl-D-aspartate (NMDA) receptor 2B gene (GRIN2B) was studied as a candidate gene of alcoholism. This study aimed to investigate the association between each of the three GRIN2B polymorphisms (rs1806201, rs1805247, and rs1805502) and alcoholism. This study included 206 alcoholic patients and 189 unrelated control subjects of Korean origin. Associations between genotype, allele, and haplotype frequencies of the polymorphisms and alcoholism were investigated. The genotype frequencies of rs1806201 and the haplotype analysis of SNPs in this study show significantly differences between the case and controls. These findings suggest new candidate SNPs in GRIN2B for studying the genetic susceptibility to alcoholism.     

SNCA variants rs2736990 and rs356220 as risk factors for Parkinson’s disease but not for amyotrophic lateral sclerosis and multiple system atrophy in a Chinese population

Previous studies found that polymorphisms rs2736990 and rs356220 in the alpha-synuclein (SNCA) gene increase the risk for Parkinson's disease (PD) in a Caucasian population. In consideration of the overlapping of clinical manifestations and pathologic characteristics among PD, amyotrophic lateral sclerosis (ALS), and multiple system atrophy (MSA), the possible associations of these 2 polymorphisms and 3 neurodegenerative diseases were studied in the Chinese population. A total of 1011 PD, 778 sporadic ALS (SALS), 264 MSA patients, and 721 healthy controls (HCs) were studied. All subjects were genotyped for the 2 polymorphisms using polymerase chain reaction and direct sequencing. Significant differences in the genotype frequencies (p = 0.0188 and 0.0064, respectively) and minor allele frequencies (MAFs) (p = 0.0065 and 0.0095, respectively) of rs2736990 and rs356220 were observed between the PD patients and HCs. Moreover, significant differences were found between the early-onset PD patients (<50 years) and matched controls but not in the late-onset PD patients (≥50 years). However, no differences were observed between subgroups with regard to clinical features, such as sex, onset symptoms (tremor or rigidity), cognition (normal or abnormal), and anxiety and depression (presence or absence). No significant differences were found in the genotype frequencies and MAFs of these 2 single-nucleotide polymorphisms between SALS patients and HCs and between MSA patients and HCs. No significant differences were found between subgroups with regard to the clinical presentation of SALS and MSA. Our results show that rs2736990 and rs356220 in SNCA decreased the risk for PD in a Chinese population. These candidate polymorphisms were unlikely to be the causes of SALS and MSA in this population.     

Serotonin 2A receptor gene is associated with personality traits, but not to disorder, in patients with borderline personality disorder

Borderline personality disorder (BPD) is a chronic, disabling, and high-risk mental disorder characterized by a pervasive pattern of instability in regulation of emotion, interpersonal relationships, self-image, and impulse control beginning in early adulthood. BPD affects about 1%-2% of the general population and has a high mortality rate as a result of suicide and impulsive behaviour. The serotonin 2A receptor gene (HTR2A) is considered a candidate gene for BPD because multiple lines of evidence suggest that it plays an important role in suicide, impulsivity and emotional liability. To test for an association between HTR2A and BPD, we genotyped four polymorphisms, rs6313 (T102C), rs4941573, rs2296972 and rs6314 (His452Tyr), in 111 Caucasian patients with BPD and 287 Caucasian healthy controls. The program UNPHASED was used to compare allele and haplotype frequencies between cases and controls. We did not find a significant association between HTR2A and BPD based on allele, genotype or haplotype analyses. However, there were significant associations between HTR2A and personality traits in the BPD patients. The C allele of rs6313 and the A allele of rs4941573 associated with a higher Extraversion score. Our results suggest that the serotonin 2A receptor gene may not play a major role in the aetiology of borderline personality disorder, but may have a role in personality traits.     

The promoter polymorphisms of receptor for advanced glycation end products were associated with the susceptibility and progression of sepsis

Receptor for advanced glycation end products (RAGE) is considered a major pattern recognition receptor, which plays an important role in the development of sepsis. Increasing evidence showed an association between RAGE polymorphisms and the susceptibility to several inflammatory‐related diseases. However, little is known about the clinical relationship between RAGE polymorphisms and sepsis. In this study, we analyzed the association of sepsis with three functional RAGE gene polymorphisms (rs1800624, rs1800625 and rs2070600) in a Chinese Han population (372 sepsis cases and 400 healthy controls). Significant differences were observed in the rs1800624 and rs1800625 genotype/allele distributions between the sepsis and controls, but no significant difference was observed in the rs2070600 genotype/allele. Moreover, our results also revealed a significant difference in the genotype/allele frequencies of the rs1800624 and rs1800625 polymorphisms between the sepsis and severe sepsis subtypes, the rs1800624 TT or rs1800625 TT genotype carriers exhibited a significant increase in RAGE mRNA, sRAGE, TNF‐α and IL‐6 expression compared with the rs1800624 AT/AA or rs1800625 CT/CC carriers in sepsis patients. Overall, this study might provide valuable clinical evidence between the RAGE gene polymorphisms and the risk or the development of sepsis.     

CYP2C19、CYP3A5基因多态性与心肌梗死的相关性研究

目的探讨CYP2C19、CYP3A5基因的多态性与心肌梗死发病风险的相关性。方法随机选取心肌梗死患者及健康对照各500例,采用荧光PCR法和Sanger测序分别检测其CYP2C19、CYP3A5基因的多态性,用Logistic回归分析其与心肌梗死的相关性,用Quanto软件评估统计学效能。结果CYP2C19基因rs4986893位点的AG、GG基因型和A等位基因的频率以及CYP3A5基因rs776746位点的AA、AG、GG基因型和G等位基因频率在两组之间的差异具有统计学意义(P<0.05),CYP2C19基因rs4244285、rs12248560位点的基因型和等位基因以及rs4986893位点的AA基因型的频率在两组之间差异无统计学意义(P>0.05)。在校正年龄、性别、体质指数后,Logistic回归分析显示CYP2C19基因rs4986893的AG基因型和A等位基因以及CYP3A5基因rs776746的GG基因型和G等位基因可能是心肌梗死发病的风险因素,而rs4986893的GG基因型以及rs776746的AA、AG基因型可能是心肌梗死的保护因素。依据样本量、样本结构和等位基因频率以及Quanto分析,本研究的结果具有理想的统计学效能(99%)。结论CYP2C19、CYP3A5基因的多态性可能增加心肌梗死的发病风险。     

Association of a polymorphism in the Homer1 gene with cocaine dependence in an African American population

OBJECTIVE: While twin and adoption studies have demonstrated that up to 70% of the risk for becoming addicted to cocaine is due to genetic factors, identifying specific genes involved in the development or progression of cocaine dependence has been difficult. The purpose of this study is to determine whether single-nucleotide polymorphisms in the Homer1 and Homer2 genes associate with the cocaine-dependent phenotype in an African American population. METHODS: This study utilized a case-control design in which the genotype and allele frequencies for four single-nucleotide polymorphisms in the Homer1 gene and three single-nucleotide polymorphisms in the Homer2 gene were compared between African American individuals with a diagnosis of cocaine dependence (n=170) and African American individuals with no history of substance abuse (n=90). RESULTS: The data indicate that one single-nucleotide polymorphism, rs6871510, located in intron 1 of the Homer1 gene significantly (P=0.029) associates with cocaine dependence at the genotype level, and trends toward a significant association at the allele frequency level (chi=2.62, df=1, P=0.106, OR=1.71). None of the single-nucleotide polymorphisms analyzed in the Homer2 gene associates with cocaine dependence. CONCLUSIONS: The results of this study suggest that a polymorphism in the Homer1 gene, rs6871510, is a potential risk factor for the development of cocaine dependence in an African American population, whereas polymorphisms in the Homer2 gene are not.     

网状蛋白4基因rs2588519 T/C和rs7582359 A/G多态性在广西人群中的分布

目的研究广西人群中网状蛋白4(RTN4)基因rs2588519 T/C及rs7582359 A/G位点多态性的分布特征,对比分析不同种族间这两个位点基因型及等位基因频率的分布差异。方法运用多重单碱基延伸技术和DNA测序方法检测323例广西健康体检者的RTN4基因rs2588519 T/C及rs7582359 A/G位点基因型,分析其基因型及等位基因频率的分布,并对比HapMap(国际人类基因组单体型图计划)公布的欧洲人、日本人、非洲人和北京人的多态性数据。结果在广西人群中,RTN4基因rs2588519 T/C位点存在CC(53.0%)、TC(38.7%)、TT(8.3%) 3种基因型;rs7582359 A/G位点存在AA(7.4%)、AG(37.5%)、GG(55.1%) 3种基因型,这两位点的基因型及等位基因频率在男女间差异无统计学意义(P0.05)。rs2588519 T/C位点基因型与非洲人群比较差异具有统计学意义(P0.05),其等位基因则与欧洲人、日本人和非洲人差异具有统计学意义(P0.05);rs7582359 A/G位点基因型及等位基因与欧洲人、非洲人比较差异均有统计学意义(P0.05)。结论 RTN4基因rs2588519 T/C及rs7582359 A/G位点多态性分布存在不同程度的种族差异。     

广西人群miRNA-107基因多态性分布特征及其与血脂的关系

目的探讨miR-107基因单核苷酸多态性(SNP)位点rs2296616 C/T在广西地区健康人群中的分布特点,对比其在不同种族间基因型及等位基因频率分布的差异,并进一步探讨rs2296616 C/T位点单核苷酸多态性(SNP)与血脂水平的相关性。方法采用多重单碱基延伸SNP分型技术(multiplex SNa Pshot)和DNA测序法,检测372例广西健康人rs2296616 C/T位点的多态性,用7600生化仪检测其血脂相关指标,并用统计学方法分别比较rs2296616C/T位点多态性在各种族人群间的分布差异及不同基因型间的血脂水平差异。结果广西人群miR-107基因rs2296616 C/T位点存在TT(91.1%)和CT(8.9%)两种基因型及T(95.6%)和C(4.4%)两种等位基因。该位点的基因型和等位基因型频率在广西人群不同性别间的比较,差异无统计学意义(P>0.05)。其基因型和等位基因频率与人类基因组单体型图(Hap Map)所公布的欧洲人、日本人、非洲人、印第安人和墨西哥人分型数据相比较,差异均有统计学意义(P<0.05),但与北京汉族人群比较,差异无统计学意义(P>0.05)。rs2296616 C/T位点两种基因型人群血脂之间比较,携带TT基因型人群的高密度脂蛋白胆固醇(HDL-C)与CT组比较,差异具有统计学意义(P<0.05)。结论广西人群miR-107基因rs2296616 C/T位点多态性与其他种族人群之间比较存在不同程度的差异;rs2296616 C/T位点多态性与HDL-C水平高低有关。     

Meta-analysis of DRD3 gene and schizophrenia: Ethnic heterogeneity and significant association in caucasians

The involvement of dopamine in the etiology of schizophrenia is suggested by a number of neurobiological and pharmacological data, the dopamine D3 receptor (DRD3) being selectively expressed in brain regions which may be specifically involved in the risk for schizophrenia. The gene coding for DRD3 has thus been extensively analyzed. Since the initial report providing substantial evidence for an association of homozygosity of either allele of the gene coding for DRD3 (BalI polymorphisms) with schizophrenia, a flurry of replicating studies has appeared, which have been split into confirmations and nonreplications in North European Caucasian, Mediterranean, Asian, American, and African populations. The involvement of DRD3 polymorphisms thus remains questionable, particularly as no linkage studies have favored a nonrandom segregation of DRD3 alleles and schizophrenia. We performed a metaanalysis from 29 independent samples, from 24 different association studies so far published, allowing the examination of 2,619 schizophrenic patients and 2,517 controls. No significant differences of genotype counts were noted between patients and controls for the whole sample, considering frequency of any genotype. Starting from the high variability of the genotypes in different geographical areas, the impact of ethnic heterogeneity was taken into account. When the studies were reorganized in five groups according to geographical origin of samples, both homozygosity and 1-1 genotype revealed significant heterogeneity (P < 0.05). We specifically found an excess of homozygosity and 1-1 genotype in schizophrenic patients only in the African and Caucasian groups (P < 0.05). The present analysis suggests a small but significant effect of DRD3 in the susceptibility to schizophrenia, at least in Caucasians. Am. J. Med. Genet. (Neuropyschiatr. Genet.) 81:318–322, 1998. © 1998 Wiley-Liss, Inc.     

Lack of association between CD40 polymorphisms and acute rejection in German liver transplant recipients

CD40 and its ligand, CD154, are major costimulatory molecules whose interactions are important in alloreactive transplant rejection. The aim of this study was to examine the association of CD40 polymorphisms with the susceptibility to acute rejection episodes in liver transplantation. In total, 112 liver transplant recipients with biopsy proven acute rejections (BPAR), 97 without BPAR (WBPAR), and 112 healthy control individuals were enrolled in the study. Two single nucleotide polymorphisms (SNPs) of CD40 gene (rs1883832 and rs4810485) were genotyped by polymerase chain reaction-allele specific restriction enzyme analysis (PCR-ASRA). Both SNPs has been tested for a recessive and a dominant model. No significant differences were found in the genotype and allele frequencies of the SNPs rs1883832 and rs4810485 between BPAR liver recipients and WBPAR recipients. Our results do not suggest an important role of tested CD40 SNPs in the susceptibility to acute liver transplant rejection in a Caucasian population.