肿瘤坏死因子-β基因+A252G多态性与精神分裂症的关联分析

目的探讨肿瘤坏死因子-β(TNF-β)基因+A252G多态性位点与精神分裂症的关系。方法收集172个来自广东潮汕地区的精神分裂症核心家系,用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法,检测所有研究对象的TNF-β基因+A252G位点的基因频率和基因型,并进行基于单体型的单体型相对风险(HHRR)和传递不平衡检验(TDT)。结果HHRR分析结果显示,精神分裂症患者组与虚拟对照组之间+A252G位点的基因频率差异有统计学意义(2=5.28,P<0.05);TDT结果显示,杂合子父母过多地传递等位基因G给患者(2=5.49,P<0.05),提示该多态位点在精神分裂症中存在传递不平衡;按临床亚型进一步分层分析,+A252G位点只在96个偏执型分裂症家系中存在明显的传递不平衡(2=11.23,P<0.001)。结论在广东潮汕人群中,TNF-β基因+A252G位点与精神分裂症存在连锁,它可能是精神分裂症尤其是偏执型分裂症的易感基因或与之存在连锁不平衡。     

隐花色素-1基因与精神分裂症核心家系的传递不平衡分析

目的探讨精神分裂症与隐花色素-1（Cryl）基因多态性的关联关系。方法应用聚合酶链反应和限制性片段长度多态性技术对100个精神分裂症核心家系的Cryl基因上的多态性位点rs2300448、rs1921135和rs1056560进行多态性检测；用Genehunter2．1软件包进行传递不平衡分析（TDT），并构建可能的单体型。结果（1）rs2300448多态性位点等位基因G和等位基因A传递给患病子女的频率差异有统计学意义，等位基因G优先传递给患病子女（X^2=4．92，P=0．027），但P值经Bonferroni校正后，差异无统计学意义（Pc=0．054）；rs1056560和rs1921135多态性位点未发现传递不平衡现象（X^2=0．15，P=0．698；X^2=0．56，P=0．456）。（2）单体型rs2300448-rs1056560G—A（X^2=6．76，P=0．009）、rs1921135-rs2300448-rs1056560T—G—C（X^2=4．50，P=0．034）和C—G—A（X^2=6．37，P=0．012）存在传递不平衡现象，但P值经Bonferroni校正后，T—G—C和C—G—A差异均无统计学意义（Pc〉0．05），只有单体型rs2300448-rs1056560G—A差异有统计学意义（Pc=0．036）。结论Cry1基因可能与精神分裂症相关联。     

早发性精神分裂症核心家系的亚甲基四氢叶酸还原酶基因传递不平衡研究

目的:在中国汉族早发性精神分裂症家系中探讨亚甲基四氢叶酸还原酶(MTHFR)基因与精神分裂症的相关性。方法:采用聚合酶链反应-限制性片段长度多态性方法(PCR-RFLP)技术,检验111个早发性精神分裂症核心家系MTHFR基因A1298C和C677T多态性,并进行连锁不平衡检验(LD)以及传递不平衡检验(TDT)。结果:A1298C及C677T等位基因在父母与先证者间传递差异均无统计学意义(χ2=0.216,P=0.642;χ2=0.143;P=0.706);连锁不平衡检验表明A1298C与C677T之间存在中度连锁不平衡(D'=0.529);单体型TDT显示早发性精神分裂症核心家系中各单体型传递差异均无统计学意义(P>0.05)。结论:MTHFR基因A1298C及C677T多态性与早发性精神分裂症无明显关联。     

PLA2G6基因多态性与偏执型精神分裂症的关联

目的：探讨PLA2G6基因多态性与偏执型精神分裂症的关系.方法：采用聚合酶链反应（PCR）和限制性内切酶片段长度多态性（RFLP）方法,在109个偏执型精神分裂症患者核心家系中检测PLA2G6基因上的3个单核苷酸多态性（SNP）（rs2235346、rs2272831和rs2284060）.运用单倍型相对风险（HRR）分析和传递不平衡分析（TDT）方法进行关联分析.结果：所检测的3个SNPs的基因型在患者组和父母组中频数分布均符合Hardy-Weinberg平衡.HRR和TDT分析均表明,rs2272831位点与偏执型精神分裂症相关联（χ^2=5.590,υ=1,P=0.018;χ^2=5.333,υ=1,P=0.021）,而rs2235346和rs2284060位点与偏执型精神分裂症无关联.结论：PLA2G6基因可能是偏执型精神分裂症的易感基因.     

精神分裂症与Xp11区HSU93305基因座的单体型及22 q11～13区相关基因的关联性研究

目的探讨Xp11区HSU93305基因座单体型、22 q11～13区α2肾上腺素能受体(A2αR)基因和儿茶酚-氧-甲基转移酶(COMT)基因多态性与精神分裂症的关联.方法分别提取59个中国汉族核心家系成员(母59名,父56名,精神分裂症患者59例)的DNA,采用基因扩增和限制性片段长度多态性技术,进行HSU93305基因座的单体型研究;选择其中56个父母均存活的家系进行A2αR基因和COMT基因多态性传递不平衡检验(TDT)的研究,并应用复等位基因TDT、基于单体型的单体型相对风险率(HHRR)检验等.结果 (1)Xp11区HSU93305基因座经Msp Ⅰ及Dra Ⅱ酶切后产生四种单体型D1M1,D1M2,D2M1,D2M2.父母组以单体型D2M1频率最高(57.7%);患者组也以D2M1传递率最高(59.0%),其次为D1M2(28.9%),D2M2传递率最低(1.2%).(2)经复等位基因TDT分析,精神分裂症与Xp11区HSU93305基因座相关联(χ2=9.28,v=3,P<0.05);与A2αR基因(χ2=1.09,v=1,P>0.05)和COMT基因(χ2=0.31,v=1,P>0.05)未见关联.(3)经HHRR检验,A2αR基因(χ2=1.21,v=1,P>0.05)和COMT基因(χ2=0.37,v=1,P>0.05)与精神分裂症亦未见关联.结论精神分裂症与HSU93305基因座相关联,其易感基因可能位于Xp11区;与A2αR基因和COMT基因多态性可能无关.     

精神分裂症和亚甲基四氢叶酸还原酶基因的核心家系研究

目的探讨亚甲基四氢叶酸还原酶(MTHFR)基因与中国西北地区汉族精神分裂症的关系。方法应用聚合酶链反应-限制性片段长度多态性方法(PCR-RFLP),检测106个精神分裂症核心家系MTHFR基因的C677T和A1298C多态性,采用单倍体相对风险(HRR)和传递不平衡检验(TDT)分析MTHFR基因与精神分裂症的关系。结果①患者组与父母组MTHFR基因C677T和A1298C多态性基因型频率分布差异无统计学意义(x2=0.369,P>0.05;x2=1.214,P>0.05)。②HRR分析显示C677T、A1298C两位点等位基因在病例组和父母对照组的频数分布差异无统计学意义(x2=0.236,P>0.05;x2=3.327,P>0.05)。③TDT检验未发现C677T和A1298C两位点在精神分裂症中存在传递不平衡(x2=0.243,P>0.05;x2=2.123,P>0.05)。结论未发现MTHFR基因C677T和A1298C多态性与精神分裂症存在关联。     

精神分裂症和心境障碍混合家系MLC1基因多态性的关联研究

目的在中国汉族人群精神分裂症和心境障碍混合家系中探讨位于22q13的MLC1基因多态性(rs11568171、rs2076137及rs2235349)与精神分裂症、心境障碍的关系。方法在有精神分裂症和心境障碍混合遗传家族史的67个核心家系(包括44个完整的核心家系)中,采用聚合酶链式反应和限制性片断长度多态性(PCR-RFLP)方法,分析MLC1基因上述多态性的基因型及其单体型,进行传递不平衡检验(TDT)。结果患者组与父母组之间,MLC1基因rs11568171T/C、rs2076137T/C及rs2235349T/C多态性等位基因和基因型分布差异无统计学意义(P>0.05),且TDT结果示各多态性在精神分裂症或心境障碍组中父母与患者之间等位基因传递差异均无统计学意义(P>0.05)。单体型TDT显示,精神分裂症患者组中父母与患者之间单体型T-C-T明显传递过少(2=5.0,P<0.05),而单体型C-C-C明显传递过多(2=5.0,P<0.05)。结论在中国汉族人群中MLC1基因可能是精神分裂症的易感基因,但可能不是心境障碍的易感基因。     

肿瘤坏死因子α启动子基因多态性与胸腺瘤的相关性

目的研究肿瘤坏死因子(TNF)-α启动子基因多态性与胸腺瘤发病的相关性。方法采用聚合酶链反应加基因测序技术对126例胸腺瘤患者与245名健康对照者TNF-α启动子区进行基因分型,比较TNF-α-863、-308、-238、-806以及-857 5个位点等位基因出现频率的差异。结果胸腺瘤患者TNF-α基因-857位点T等位基因和CT+TT基因型显著高于健康对照组(分别为χ2=6.449,P=0.011;χ2=4.874,P=0.027),而TNF-α-863、-308、-238、-806等位点的等位基因频率与健康对照组比较差异无统计学意义。结论 TNF-α基因-857位点T等位基因与胸腺瘤相关,且其可能为胸腺瘤患者一个新的易感基因标记。     

TNF-α启动子-308位点多态性与重症肌无力的相关性

目的探讨肿瘤坏死因子(tumor necrosis factor,TNF)-α启动子区域-308位点基因多态性与重症肌无力(myasthenia gravis,MG)的相关性。方法采用聚合酶链反应及基因测序技术检测289例MG患者与304名健康对照者TNF-α-308位点的基因型及等位基因分布频率,进一步根据MG患者性别、年龄、临床分型等进行分组,比较各组间TNF-α-308位点基因型及等位基因分布频率的差异。结果 MG患者及健康对照组均未发现A/A基因型;MG患者TNF-α启动子-308位点G/A基因型和等位基因A出现的频率与健康对照组比较差异无统计学意义(P>0.05)。相同性别间比较,男性MG组G/A基因型(P=0.025,OR=2.673,95%CI:1.105～6.467)及A等位基因(P=0.029,OR=2.533,95%CI:1.071～5.991)出现的频率高于健康对照组;发病年龄<40岁的MG组,全身型G/A基因型(P=0.004,OR=4.760,95%CI:1.533～14.778)及A等位基因(P=0.005,OR=4.298,95%CI:1.450～12.740)出现的频率高于眼肌型。结论 TNF-α-308位点多态性与中国北方地区男性MG患者及早发全身型MG患者发病相关。     

肿瘤坏死因子-α-308基因多态性与广东汉族人颅内动脉瘤的相关性研究

目的探讨广东汉族人群肿瘤坏死因子(TNF)-α-308基因多态性与颅内动脉瘤(IA)的相关性。方法采用聚合酶链-限制性片段长度多态性(PCR-RFLP)方法检测115例IA患者与100名健康对照者TNF-α-308基因多态性,并对两组人群中该基因的基因型频率进行比较。结果在IA患者中,G/G基因型有87例(75.7%),G/A基因型有28例(24.3%);在对照组中,G/G基因型有88名(88.0%),G/A基因型有12例(12.0%)。TNF-α-308基因型频率在病例组与正常对照组差异有统计学意义(P<0.05)。关联分析显示A等位基因携带者患IA的风险较正常对照者升高2.36倍(OR=2.36,95%CI=1.13～4.94)。结论TNF-α-308基因多态性与中国广东汉族人群IA的发生具有相关性,该基因可能是广东汉族人IA的易感基因之一。     

No association between the tumor necrosis factor-alpha gene promoter polymorphisms and schizophrenia in a Japanese population

Tumor necrosis factor-alpha (TNF-alpha) is a pleiotrophic cytokine and exerts neuroprotective and neurodegenerative effects in brain. Several studies have indicated that TNF-alpha is likely related to the pathogenesis of schizophrenia. Recent genetic investigations have revealed that a TNF-alpha gene promoter polymorphism (-G308A) is associated with schizophrenia, although negative findings have also been reported. To assess whether the TNF-alpha gene promoter variants including -G308A could be implicated in vulnerability to schizophrenia, we conducted a case-control association analysis (265 cases and 424 controls) and the transmission disequilibrium test (TDT) analysis (83 trios) for four polymorphisms (-G238A, -G308A, -C857T and -T1031C) in Japanese subjects. In a case-control analysis, there was no significant association between the promoter polymorphisms or haplotypes in the TNF-alpha gene and schizophrenia. In the TDT analysis, we also did not observe transmission distortion. Our results suggest that the above four polymorphisms in the promoter region of the TNF-alpha gene appear not to confer increased susceptibility for schizophrenia in a Japanese population.     

Association of tumor necrosis factor alpha gene -G308A polymorphism with schizophrenia

BACKGROUND: Tumor necrosis factor alpha (TNFalpha), a cytokine involved in inflammatory processes, has been implicated in the pathophysiology of schizophrenia. The chromosomal location in the major histocompatibility complex (MHC) region on 6p21.1-21.3, a region with evidence for linkage, suggests a role in susceptibility to schizophrenia. Association of the minor (A) allele of the -G308A TNFalpha gene polymorphism with schizophrenia has been reported [Mol. Psychiatry 6 (2001) 79]. METHODS: Association of the -G308A TNFalpha gene and the lymphotoxin alpha (LTalpha)+A252G gene polymorphisms with schizophrenia was studied in 79 sib pair families with linkage in the MHC region and in 128 trio families using the transmission disequilibrium test (TDT). RESULTS: Weak association of the common G allele was detected for TNFalpha -G308A in both samples independently with borderline significance in the sib pair families (0.064) and with a nominally significant value of P=0.022 in the trio families. Combining both samples produced P=0.003, while LTalpha+A252G, located approximately 2-3 kb distally, revealed P=0.03 and the two locus haplotype yielded a P value of 0.001. CONCLUSION: Our data suggests association of the common G allele of the -G308A TNFalpha gene polymorphism with schizophrenia in a sample of 207 families. However, linkage disequilibrium with a different allele of the TNFalpha gene or another gene in the MHC region cannot be excluded.     

Cytokine gene polymorphisms in obstructive sleep apnoea/hypopnoea syndrome

ObjectiveThe pro-inflammatory cytokines, TNF-α, IL-6, and IL-8 are elevated in obstructive sleep apnoea/hypopnoea syndrome (OSAHS). Cytokine gene interactions are complex and haplotype analysis may be more informative. We hypothesized that the effects of TNF-α in OSAHS might be due to linkage disequilibrium of the TNF-α (−308A) single nucleotide polymorphism (SNP) with other polymorphisms within the TNF-α gene, and that predisposition to elevated IL-6 and IL-8 levels in OSAHS might be attributable to pro-inflammatory IL-6 and IL-8 gene promoter polymorphisms.Method173 subjects were classified as having definite OSAHS or not on the basis of apnoea–hypopnoea frequency, sex, age, and symptoms. Population controls comprised 192 random UK blood donors. Genotyping was undertaken for the TNF- α promoter polymorphisms (−1031, −863, −857, −238), two lymphotoxin-α polymorphisms (intron 1 and Thr60Asn), the pro-inflammatory IL-6 gene promoter polymorphism (−174), and IL-8 gene promoter polymorphisms (−251; −781).ResultsThere was no significant difference between groups re: genotype/allelic frequency in the genes investigated. Association between disease status and the TNF-α alleles independently (TNF-103, TNF-803, TNF-857, TNF-238) with five haplotypes of TNF-α was not significant (p > 0.05). There was no difference in allelic or genotypic frequencies between obese and non-obese subjects with OSAHS. The TNF- α (−863A) allele alone, was significantly associated with obesity (OR 2.4; CI95% 1.1–5; p = 0.025).ConclusionOnly the TNF- α (308A) SNP appears to be significantly associated with OSAHS. The impact of cytokine gene polymorphisms on phenotypic expression of inflammation in OSAHS is likely to be complex.     

Linkage disequilibrium between dopamine D1 receptor gene (DRD1) and bipolar disorder.

BACKGROUND: Based on the dopamine hypothesis, the dopamine D1 receptor gene (DRD1) is considered to be a good candidate gene for bipolar disorder (BP). METHODS: In our study, three polymorphisms of the DRD1 gene, -800T/C, -48A/G, and 1403T/C, were analyzed in 286 BP trios. Both the transmission disequilibrium test (TDT) and haplotype TDT were performed on the genotype data to test for the presence of linkage disequilibrium between DRD1 and bipolar disorder. With the extended transmission disequilibrium test (ETDT), we also calculated the maternal transmission and paternal transmission for each allele. RESULTS: Although no association was found for each individual polymorphism, there is a significant association between DRD1 and BP for haplotype TDT analysis (chi(2) = 16.068, df = 3, p =.0011). CONCLUSIONS: These results indicate that DRD1 may play a role in the etiology of bipolar disorder.     

Transmission disequilibrium test and haplotype analysis of the NOTCH4 gene in Japanese patients with schizophrenia

A recent study reported that the NOTCH4 gene was highly associated with schizophrenia in the British population. To confirm this association for another population, a case-control study was conducted and a transmission disequilibrium test (TDT) analysis was performed on a group of Japanese subjects (235 pairs of schizophrenia patients and controls, and 78 trios consisting of probands and their parents) using two single nucleotide polymorphisms and three microsatellite markers for the NOTCH4 gene. Haplotype analysis was also studied in case-control and family based data sets. In all markers except for (CTG)n (P = 0.012, before correction for multiple testing), no differences were found in the case-control study. The TDT analysis also revealed only a weak transmission disequilibrium in (TTAT)n (genotype-wise P = 0.012). The finding of the present study could not support the original findings that the NOTCH4 gene itself is associated with susceptibility to schizophrenia.     

Tumor necrosis factor promoter haplotype associated with schizophrenia reveals a linked locus on 1q44

Using restriction fragment length polymorphism and pyrosequencing methods, we genotyped two TNFA gene promoter SNPs (-G308A, -G238A) and analyzed the haplotype structure in 24 Canadian families of primarily Celtic origin. Our results demonstrate that after correction for multiple testing based on simulations of 10 000 replicates of unlinked/unassociated data, there is evidence for association (P=0.026) of a specific haplotype (-308A, -238G) with schizophrenia and schizophrenia spectrum disorders with a family-based trimmed haplotype linkage disequilibrium test (Trimhap). Stratifying the 22 families with genome scan data by TNFA promoter haplotypes followed by reanalysis of linkage to schizophrenia throughout the genome, we identified few loci that exhibit a considerable increase in LOD/HLOD scores. A locus on chromosome 1q44 (D1S1609) demonstrated a significant increase (P=0.025) in LOD score from 0.15 to 3.01 with a broad definition of the schizophrenia phenotype and a dominant mode of inheritance. This result replicates a previously reported positive result of linkage of schizophrenia spectrum disorders to this area of the genome. We also illustrated that simulation studies are pivotal in evaluating the significance of results obtained with newer statistical methods, when multiple, but not independent, tests are performed, and when sample stratification is utilized to reduce the impact of heterogeneity or assess the interaction between loci.     

偏执型分裂症外周血IL-1β、TNF-α和酪氨酸羟化酶mRNA表达水平与临床症状的关系

目的检测偏执型精神分裂症患者白介素-1β、肿瘤坏死因子-α和酪氨酸羟化酶（TH）的基因表达水平,探讨其与临床症状的关系。方法采用RT-PCR和半定量技术,分别检测39例偏执型精神分裂症患者和30例正常对照外周血单个核细胞IL-1β、TNF-α和TH的基因表达水平,同时应用PANSS量表评定偏执型精神分裂症患者临床症状。结果研究显示病例组的IL-1β、TNF-α、TH基因表达水平均显著高于正常对照组（P〈0.01）。且同时发现IL-1β（r=0.420）、TNF-α（r=0.430）基因表达水平与PANSS量表的一般病理症状分显著相关（P〈0.01）。结论偏执型精神分裂症患者可能存在致炎性细胞因子和儿茶酚胺类神经递质的过度表达;致炎性细胞因子可能参与偏执型精神分裂症一般病理症状的形成。     

Family-based linkage disequilibrium mapping using SNP marker haplotypes: application to a potential locus for schizophrenia at chromosome 22q11

Family-based linkage disequilibrium mapping using SNP markers is expected to be a major route to the identification of susceptibility alleles for complex diseases. However there are a number of methodological issues yet to be resolved, including the handling of extended haplotype data and analysis of haplotype transmission in sib-pair or family trio samples. In the present study, we have analysed two dinucleotide repeat and six SNP markers at the COMT locus at chromosome 22q11, a region implicated in psychosis, for transmission distortion in 198 Chinese schizophrenic family trios. When individual markers were analysed using the TDT, two showed modest evidence of transmission distortion (186C/T, P = 0.04; Val158Met, P = 0.01). Using haplotypes of paired markers analysed by the program TRANSMIT, the most significant P value was 0.001, for the Met158Val and 900ins/delC polymorphisms in the COMT gene. The global P value for the haplotypes of all six SNP markers tested was 0.004, largely a result of the excess transmission of two extended haplotypes which differed at the marker 408C/G. The exclusion of this marker from the analysis gave a global P value of 0.002 and produced a five marker haplotype system which was significant at P = 0.0006. This haplotype consisted of the alleles -287G:186C:Val158:900insC:ARVCF930C, which may represent a background haplotype for the transmission of a schizophrenia susceptibility allele at chromosome 22q11. Our results support the hypotheses that either COMT is itself a susceptibility gene, or more likely that this region of chromosome 22 contains a susceptibility gene that is in linkage disequilibrium with COMT alleles. Molecular Psychiatry (2000) 5, 77-84.