Evidence of common and specific genetic effects: association of the muscarinic acetylcholine receptor M2 (CHRM2) gene with alcohol dependence and major depressive syndrome

Several correlated phenotypes, alcohol dependence, major depressive syndrome, and an endophenotype of electrophysiological measurements, event-related oscillations (EROs), have demonstrated linkage on the long arm of chromosome 7. Recently, we reported both linkage and association between polymorphisms in the gene encoding the muscarinic acetylcholine receptor M2 (CHRM2) and EROs. In this study, we evaluated whether genetic variation in the CHRM2 gene is also a risk factor for the correlated clinical characteristics of alcoholism and depression. The CHRM2 gene contains a single coding exon and a large 5' untranslated region encoded by multiple exons that can be alternatively spliced. Families were recruited through an alcohol dependent proband, and multiplex pedigrees were selected for genetic analyses. We examined 11 single nucleotide polymorphisms (SNPs) spanning the CHRM2 gene in these families. Using the UNPHASED pedigree disequilibrium test (PDTPHASE), three SNPs (one in intron 4 and two in intron 5) showed highly significant association with alcoholism (P=0.004-0.007). Two SNPs (both in intron 4) were significantly associated with major depressive syndrome (P=0.004 and 0.017). Haplotype analyses revealed that the most common haplotype (>40% frequency), T-T-T (rs1824024-rs2061174-rs324650), was under-transmitted to affected individuals with alcohol dependence and major depressive syndrome. Different complementary haplotypes were over-transmitted in alcohol dependent and depressed individuals. These findings provide strong evidence that variants within or close to the CHRM2 locus influence risk for two common psychiatric disorders.     

Association of the Catechol-o-Methyltransferase Gene Polymorphisms with Korean Autism Spectrum Disorders

This study evaluated the family-based genetic association between autism spectrum disorders (ASDs) and 5 single-nucleotide polymorphisms (SNPs) in the catechol-o-methyltransferase gene (COMT), which was found among 151 Korean ASDs family trios (dominant model Z = 2.598, P = 0.009, P_FDR = 0.045). We found a statistically significant allele transmission or association in terms of the rs6269 SNP in the ASDs trios. Moreover, in the haplotype analysis, the haplotypes with rs6269 demonstrated significant evidence of an association with ASDs (additive model rs6269-rs4818-rs4680-rs769224 haplotype P = 0.004, P_FDR = 0.040). Thus, an association may exist between the variants of the COMT gene and the occurrence of ASDs in Koreans.     

A family-based association study of the myelin-associated glycoprotein and 2',3'-cyclic nucleotide 3'-phosphodiesterase genes with schizophrenia

A recent surge of evidence implicating myelin abnormalities in the etiology of schizophrenia has been found. This study is a family-based genetic association analysis examining the myelin-associated glycoprotein (MAG) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) genes in schizophrenia. About 246 families of primarily European-Caucasian origin were genotyped for MAG rs2301600, rs720308, rs720309, rs756796, and CNP rs2070106 single nucleotide polymorphisms (SNPs). The FBAT program (v1.7.2) and Transmit were used to analyze individual SNPs and haplotypes, respectively. The CNP SNP (rs2070106) was potentially associated with schizophrenia (P=0.027). MAG variants were not associated with disease transmission based on single marker or haplotype analysis. A significant maternal parent-of-origin effect for the CNP risk allele for schizophrenia was found (P=0.003). No CNP-MAG gene-gene interaction conferred increased risk for schizophrenia. Our finding provides support for potential association of the CNP gene but not the MAG gene in schizophrenia in a Caucasian population.     

抑郁症与cAMP反应元件结合蛋白基因的关联研究

目的 探讨cAMP反应元件结合蛋白(cyclic adenosine monophosphate response elementbinding protein,CREB1)基因与抑郁症的关联关系.方法 采用聚合酶链反应-限制性片段长度多态性方法检测105个抑郁症核心家系CREB1基因上单核苷酸多态性(single nucleotide polymorphisms,SNP)rs10932201和rs6740584的等位基因与基因型分布情况.进行单位点及单倍型的传递/不平衡检验(transmission disequilibrium test,TDT).结果 CREB1基因上SNP位点rs10932201和rs6740584与抑郁症均无显著性关联,TDT χ2 值分别为2.700(P=0.1004)和0.458(P=0.4986),差异均无统计学意义.单倍型TDT分析结果显示由rs10932201和rs6740584构成的单倍型与抑郁症存在显著性关联,差异有统计学意义(总χ2=23.458,df=3,P=0.00003241).单个单倍型A-C和A-T与抑郁症也均有显著性关联,差异有统计学意义(χ2 值分别为5.405和13.623,P值分别为0.020和0.00022).结论 CREB1基因上SNP位点rs10932201和rs6740584与抑郁症均无显著性关联,但由这2个SNP位点构成的单倍型与抑郁症存在显著性关联,提示CREB1基因rs10932201-rs6740584单倍型可能在抑郁症的遗传学发病机制中具有重要作用.     

A study of the PEMT gene in schizophrenia

The phospholipid hypothesis of schizophrenia is becoming popular because of the findings from the niacin flush test, the treatment with polyunsaturated fatty acids (PUFAs), biochemical studies for the phospholipid metabolism pathway and genetic studies of phospholipase A2. The present study attempted to investigate the gene coding for phosphatidylethanolamine N-methyltransferase (PEMT), which is an important enzyme for the synthesis of membrane phospholipids. We recruited 271 Chinese parent-offspring trios of Han descent and detected 3 single nucleotide polymorphisms (SNPs) at the PEMT locus. The transmission disequilibrium test (TDT) showed allelic association for rs464396 (X2=9.4, P=0.002), but not for the other two. The 2-SNP haplotype analysis showed haplotypic association for both the rs936108-rs464396 haplotypes (X2=25.7, d.f.=3, P=0.00001) and the rs464396-rs4244593 haplotypes (X2=17.3, d.f.=3, P=0.0006). The 3-SNP haplotype analysis also showed a haplotypic association (X2=24.4, d.f.=7, P=0.0006). The present results suggest that the PEMT gene may contribute to the etiology of schizophrenia.     

Family-based association study between GRIK2 polymorphisms and autism spectrum disorders in the Korean trios

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with strong genetic components. The present study comprises the detection of four single nucleotide polymorphisms (SNPs) in GRIK2 followed by a family-based association analysis of the SNPs in 126 Korean ASD trios by using the transmission disequilibrium test (TDT) and haplotype analysis. We found preferential transmission of the C allele at the rs3213607 (P<0.001) of GRIK2 in ASD and haplotype analysis revealed that one haplotype demonstrated a significant association (P=0.023). These results suggest a potential association between GRIK2 and ASD in the Korean population.     

DIO2基因单核苷酸多态性与精神发育迟滞相关性研究

目的探讨DIO2基因多态性及单倍型与精神发育迟滞的相关关系。方法本研究以344个汉族精神发育迟滞患者及其亲属组成的家系为研究对象．在DIO2上选择了3个合适的SNPs作为标记．利用PCR—SSCP和PCR—RFLP方法完成基因分型。应用FBAT软件对多态位点及可能组成的单倍型与精神发育迟滞的关系进行分析。结果单个位点家系关联性分析结果提示：rs225015、rs225014和rs225012位点各等位基因从亲代传递给患病子代没有观察到显著性（P〉0．05）。多态性位点间的连锁不平衡检验显示：3个位点rs225015、rs225014和rs225012均具有较高的连锁不平衡（D’〉0．8）。单倍型分析结果显示：3个位点构成的单体型GTG在附加遗传模型（Z=2．226,P=0．026019）和隐性遗传模型（Z=2．651,P=0．008023）与MR相关。结论DIO2基因可能与精神发育迟滞的易感性有关。     

The transmission disequilibrium analysis between neuronal nicotinic acetylcholine receptor alpha 7 subunit gene polymorphisms and schizophrenia]

OBJECTIVE: To investigate the association between neuronal nicotinic acetylcholine receptor alpha 7 subunit (CHRNA7) gene and schizophrenia. METHODS: The three polymorphisms rs2337980, rs1909884, rs883473 in CHRNA7 gene were detected based on PCR and polyacrylamide gel microarray in 129 schizophrenic trios. The results of genotyping were analyzed by haplotype relative risk analysis based on haplotype(HHRR), transmission disequilibrium test(TDT) and hyplotype analysis. RESULTS: (1)The HHRR analysis suggested that there was significant differences in rs2337980 allele frequencies between schizophrenia group and dummy control group(P= 0.017); (2)In TDT test, there may be transmission disequilibrium between rs2337980 and schizophrenia, the heterozygous parents excessively transferred the C allele to patients (P= 0.021); (3)The haplotype between rs2337980 and rs1909884 as well as the hyplotype among rs2337980, rs1909884 and rs883473 may have significant association with schizophrenia (global P= 0.034; global P= 0.027), the T-C and T-C-T hyplotype may have transmission disequilibrium with schizophrenia. CONCLUSION: There may be association between CHRNA7 gene polymorphisms and schizophrenia, the variant allele T in rs2337980 may have a protective effect to schizophrenia.     

Family-based association study of TPH1 and TPH2 polymorphisms in autism.

The TPH1 and TPH2 genes encode the rate-limiting enzymes that control serotonin biosynthesis, and serotonin is clearly altered in autism. In the current study, eight SNPs in the TPH1 gene region and eight SNPs within the TPH2 gene were examined by family-based association tests in a large cohort of 352 families with autism and in clinically defined subsets of these families with either severe obsessive-compulsive behaviors (sOCB) or self-stimulatory behaviors (SSB). We found no evidence for association between autism and single SNPs or haplotypes of the TPH1 and TPH2 genes in the cohort of all families or in the sOCB and SSB subsets. In particular, we failed to replicate the association between autism and variants of the TPH2 gene, rs4341581 (TRANSMIT P = 1; PDT P = 0.323; FBAT P = 0.446) and rs11179000 (TRANSMIT P = 0.174; PDT P = 0.293; FBAT P = 0.374). Furthermore, no evidence for linkage was observed between autism and SNPs in the TPH1 and TPH2 genes (although linkage at the TPH2 locus was observed in the SSB subset). Thus, it appears unlikely that the TPH1 and TPH2 genes play a significant role in the susceptibility to autism or to autism endophenotypes including sOCB and SSB.     

神经型烟碱乙酰胆碱受体α7亚单位基因多态性与精神分裂症的传递不平衡研究

目的 探讨神经型烟碱乙酰胆碱受体α7亚单位基因(neuronal nicotinic acetyleholine receptor α7 subunit gene,CHRNA7)多态性与精神分裂症的关系.方法 应用聚合酶链反应及聚丙烯酰胺凝胶芯片技术检测129个精神分裂症先证者核心家系CHRNA7基因的rs2337980、rs1909884、rs883473三个单核苷酸多态性,并采用基于单倍型的单倍型相对风险检验(haplotype relative risk,HHRR)、传递不平衡检验(transmission disequilibrium test,TDT)及单倍型分析进行统计.结果 (1)HHRR分析结果显示rs2337980位点精神分裂症患者组与虚拟对照组之间等位基因频率差异有统计学意义(P=0.017);(2)TDT分析发现,rs2337980位点与精神分裂症之间可能存在传递不平衡,杂合子父母过多的传递等位基因C给患病子女(P=0.021).(3)单倍型分析发现,rs2337980、rsl909884及rs2337980、rsl909884、rs883473组成的单倍型与精神分裂症有显著相关(总体P=0.034;glohal P=0.027),其中T-C,T-C-T两个单倍型与精神分裂症可能存在传递不平衡.结论 CHRNA7 基因多态性可能与精神分裂症存在关联,rs2337980的变异等位基因T可能是精神分裂症的保护性因子.     

Correlation of complement factor H gene polymorphisms with exudative age-related macular degeneration in a Chinese cohort

To evaluate the association between complement factor H (CFH) gene polymorphism and the risk of exudative age-related macular degeneration (AMD) in a case-control study in a Chinese cohort. One hundred and thirty-six exudative AMD patients and 140 age- and sex-matched control subjects were recruited. We genotyped 3 common single nucleotide polymorphisms (SNPs), namely, -257C>T (rs3753394), Y402H (rs1061170) and IVS15 (rs1329428), genetic analyses were performed on all available genotype data. All the possible haplotypes of these 3 SNPs were detected. Polymerase chain reaction (PCR) and allele-specific restriction endonuclease digestion were performed, some PCR products of these 3 SNPs were sequenced. The risk alleles (T, C or G) of the 3 SNPs conferred 1.72-fold, 3.14-fold, and 1.79-fold of increased likelihood of the disease, respectively (P<0.05). The heterozygous genotype in rs1061170 (TC) revealed significant association, meanwhile rs3753394 and rs1329428 had a slight association with the disease, respectively. Significant differences were shown in the risk alleles in the 3 SNPs among different Chinese cohort. Low linkage disequilibrium was found among the 3 SNPs. The haplotypes TCG and CTG revealed as risk factors, whereas the protective haplotype CTA was over-represented in controls. We found significant association between risk alleles (T, C or G) of the 3 SNPs and the disease. The genetic divergence across multiple populations within Chinese existed. Risk haplotypes and protective haplotype were found in this study.     

Positive association of the human frizzled 3 (FZD3) gene haplotype with schizophrenia in Chinese Han population.

Frizzled 3 (FZD3) gene is located on chromosome 8p21, a region that has been implicated in schizophrenia in genetic linkage studies. The FZD3 is a transmembrane receptor required for Wnt signal transduction cascades that have been thought to be involved in producing the cytoarchitectural defects observed in schizophrenia. Previous work has showed a strong association between FZD3 locus and schizophrenia in family-based study. To confirm this issue further, we investigated a genetic association between four single nucleotide polymorphisms (SNPs) located in the FZD3 gene and schizophrenia by case-control study using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) in the Chinese Han population. Our studies showed the SNPs rs2323019 and rs880481 have significant differences in both genotype and allele frequencies between control subjects and schizophrenic patients (rs2323019: Allele A > G, chi2 = 6.7277, df = 1, P = 0.0095; Genotype, chi2 = 10.6583, df = 2, P = 0.0049; rs880481: Allele A > G, chi2 = 10.3945, df = 1, P = 0.0013; Genotype, chi2 = 16.8049, df = 2, P = 0.0002). In addition, we constructed three-locus haplotypes to test their association with schizophrenia. The globe chi-squared test for haplotype analysis showed a significant association (chi2 = 66.38, df = 7, P < 0.000001). These results suggested that the FZD3 gene might be involved in the predisposition to schizophrenia.     

支气管哮喘易感区域5q31-33内Tim-3基因单体型分析

目的： 探讨染色体上支气管哮喘易感区域5q31-33内Tim-3基因多态性与支气管哮喘的关系。方法：应用限制性片段长度多态性技术方法,分析了118个儿童变应性哮喘核心家系Tim-3基因4个SNPs(rs10053538、rs10515746、rs13170556和rs9313441)的基因型;采用基于家系传递不平衡检验（TDT）,分析基因分型数据;应用TRANSMIT软件构建单体型并进行单体型关联分析。结果：①基于家系的TDT分析显示,Tim-3基因的4个SNPs由杂合子父母传递给患病子代的等位基因频率不比预期值高,与哮喘无关（P>0.05）。②Transmit多个位点单体型分析结果显示由Tim-3基因rs10053538、 rs13170556、 rs9313441构建的单体型与支气管哮喘有关联（Global 2=10.83,P<0.05）。父母传递给患病子女GGG单体型的观察值小于期望值,差异显著（2=8.24,P<0.01）。结论：中国汉族人群中,位于染色体5q31-33区域的Tim-3基因本身或其附近的基因可能与儿童变应性哮喘的易感性相关。     

Positive association of the <Emphasis Type="Italic">FTSJ1</Emphasis> gene polymorphisms with nonsyndromic X-linked mental retardation in young Chinese male subjects

To investigate the possible genetic association of nonsyndromic X-linked mental retardation (NS-XLMR) with FTSJ1 gene polymorphisms, a case-control association study was performed focusing on the Chinese Han population in the Qinba mountain region. Three common single nucleotide polymorphisms (SNPs) (rs2268954, rs2070991, rs5905692) in the gene were selected and genotyped using the polymerase chain reaction single-strand confirmation polymorphism (PCR-SSCP) method. Pairwise linkage disequilibrium (LD) analysis showed that the three SNPs were in strong LD (all D' > 0.8). There were significant differences between cases and controls in allele frequency distribution of rs2268954 (P = 0.036), rs2070991 (P = 0.043), and rs5905692 (P = 0.014) and in the distributions of common haplotypes combined by these SNPs (global P = 0.01236) in male subjects. In female subjects, however, no positive results were found. Our results suggest a positive association between the genetic variants of the FTSJ1 gene and NS-XLMR in young male subjects in the Chinese Han population in the Qinba region.     

Family-based association study between autism and glutamate receptor 6 gene in Chinese Han trios.

The glutamate pathways are involved in diverse processes such as learning and memory, epilepsy, and they play important roles in neural plasticity, neural development, and neurodegeneration. It has been proposed that autism could be a hypoglutamatergic disorder. Recently, Jamain et al. reported that the glutamate receptor 6 (GluR6 or GRIK2) is in linkage disequilibrium with autism. In the present study, the transmission disequilibrium test (TDT) and the haplotype transmission were performed to analyze the four SNPs (SNP1: rs995640; SNP2: rs2227281; SNP3: rs2227283; SNP4: rs2235076) of GluR6 in 174 Chinese Han parent-offspring trios. The TDT demonstrated that the two SNPs (SNP2 and SNP3) showed preferential transmission (TDT P = 0.032). The global chi(2) test for haplotype transmission also revealed an association between GluR6 and autism (chi(2) = 10.78, df = 3, P = 0.013). Our results suggested that GluR6 is in linkage disequilibrium with autism.     

The KPNA3 gene may be a susceptibility candidate for schizophrenia

The present study investigated the possible association of the KPNA3 locus in the 13q14 region with schizophrenia. We detected 7 single nucleotide polymorphisms (SNPs) on 13q14, one (rs6313) present at the HTR2A locus and the other 6 at the KPNA3 locus, among 124 British family trios consisting of mother, father and affected offspring with schizophrenia. The transmission disequilibrium test (TDT) showed allelic association for rs3736830 (chi(2)=8.66, P=0.003), rs2181185 (chi(2)=3.86, P=0.049) and rs626716 (chi(2)=5.82, P=0.016), but not for rs6313 (chi(2)=0.009, P=0.926). The global P-value was 0.029 for 1000 permutations with the TDT. The 2-SNP haplotype analysis showed a disease association for the rs2273816-rs3736830 haplotypes (chi(2)=7.63, d.f.=2, P=0.022), the rs3736830-rs2181185 haplotypes (chi(2)=10.30, d.f.=2, P=0.006) and the rs2181185-rs3782929 haplotypes (chi(2)=9.26, d.f.=2, P=0.01). The global P-value was 0.034 for 1000 permutations with the 2-SNP haplotype analysis. The 6-SNP haplotype system also showed a weak association with the illness (chi(2)=15.62, d.f.=8, P=0.048), although the 1-d.f. test did not show the association for nine individual haplotypes when a P-value was corrected by the Bonferroni corrections. The present study suggests that the KPNA3 may contribute genetically to schizophrenia in a small effect size.     

Polymorphisms in the myosin light chain kinase gene that confer risk of severe sepsis are associated with a lower risk of asthma

BACKGROUND: Myosin light chain kinase (MYLK) is a multifunctional protein involved in regulation of airway hyperreactivity and other activities relevant to asthma. OBJECTIVE: To determine the role of MYLK gene variants in asthma among African Caribbean and African American populations. METHODS: We performed association tests between single nucleotide polymorphisms (SNPs) in the MYLK gene and asthma susceptibility and total serum IgE concentrations in 2 independent, family-based populations of African descent. Previously we identified variants/haplotypes in MYLK that confer risk for sepsis and acute lung injury; we compared findings from our asthma populations to findings in the African American sepsis and acute lung injury groups. RESULTS: Significant associations between MYLK SNPs and asthma and total serum IgE concentrations were observed in the African Caribbean families: a promoter SNP (rs936170) in the smooth muscle form gave the strongest association (P = .009). A haplotype including rs936170 corresponding to the actin-binding activity of the nonmuscle and smooth muscle forms was negatively associated with asthma (eg, decreased risk) in both the American (P = .005) and Caribbean families (P = .004), and was the same haplotype that conferred risk for severe sepsis (P = .002). RNA expression studies on PBMCs and rs936170 suggested a significant decrease in MYLK expression among patients with asthma with this variant (P = .025). CONCLUSION: MYLK polymorphisms may function as a common genetic factor in clinically distinct diseases involving bronchial smooth muscle contraction and inflammation. CLINICAL IMPLICATIONS: Genetic variants in MYLK are significantly associated with both asthma and sepsis in populations of African ancestry.     

FXYD6基因遗传多态性在精神分裂症患者核心家系中的传递不平衡检验

目的 探讨FXYD6基因单核苷酸多态性(single nucleotide polymorphisms,SNP)和精神分裂症(schizophrenia)之间的相关性.方法 采用等位基因特异性PCR的方法对FXYD6基因6个SNPs(rs10790212、rs11544201、rs555577、rs1815774、rs4938446和rs497768)位点的基因型在101个三口之家中进行传递不平衡检验(transmission disequilibrium test,TDT).结果 遗传标记rs10790212和rs11544201显示了显著的传递不平衡(P＜0.05),而单倍型分析的结果表明单倍型rs10790212-rs11544201与精神分裂症显著性关联(P＜0.05).结论 FXYD6基因与中国汉族人群精神分裂症遗传易感性相关,有必要进一步开展对FXYD6基因的功能学研究.