The genetic variation of RELN expression in schizophrenia and bipolar disorder

Reelin plays an important role in the development and function of the brain and has been linked to different neuropsychiatric diseases. To further clarify the connection between reelin and psychiatric disorders, we studied the factors that influence the expression of reelin gene (RELN) and its different isoforms. We examined the total expression of RELN, allelic expression, and two alternative RELN isoforms in postmortem brain samples from patients with schizophrenia and bipolar disorder, as well as unaffected controls. We did not find a significant reduction in the total expression of RELN in schizophrenia or bipolar disorder. However, we did find a significant reduction of the proportion of the short RELN isoform, missing the C-terminal region in bipolar disorder, and imbalance in the allelic expression of RELN in schizophrenia. In addition, we tested the association between variation in RELN expression and rs7341475, an intronic SNP that was found to be associated with schizophrenia in women. We did not find an association between rs7341474 and the total expression of RELN either in women or in the entire sample. However, we observed a nominally significant effect of genotype-by-sex interaction on the variation in microexon skipping. Women with the risk genotype of rs7341475 (GG) had a higher proportion of microexon skipping, which is the isoform predominant in tissues outside the brain, while men had the opposite trend. Finally, we tested 83 SNPs in the gene region for association with expression variation of RELN, but none were significant. Our study further supports the connection between RELN dysfunction and psychiatric disorders, and provides a possible functional role for a schizophrenia associated SNP. Nevertheless, the positive associations observed in this study needs further replication as it may have implications for understanding the biological causes of schizophrenia and bipolar disorder.     

中国汉族人群中RELN基因rs7341475位点与精神分裂症的相关性分析

精神分裂症是一种常见的复杂精神疾病.大量的实验证据表明,遗传因素在精神分裂症的发生中起到了重要的作用.截至目前,有报道称至少100个基因与精神分裂症相关,但它们在不同人群中的重复性不好.在这些基因中,RELN在多个人群中都被证实与精神分裂症相关,表明它可能是一个真实的易感基因.目前,在RELN基因上有很多个单核苷酸多态性位点被证实与精神分裂症相关,其中研究最多的是通过全基因组关联分析发现的在RELN基因第四个内含子中的单核苷酸多态性位点rs7341475,它被证明与精神分裂症的发生相关.为了验证该位点在中国人群中是否与精神分裂症相关,作者对来自中国玉溪的病例——对照样本(400位患者和400位正常人)进行了遗传分析.结果显示,在该样本中rs7341475与精神分裂症不相关,这表明rs7341475在中国人群中可能不是致病多态性位点.     

Replication Study Confirms Link between TSPAN18 Mutation and Schizophrenia in Han Chinese

Schizophrenia (SCZ) is a severe psychiatric disorder associated with many different risk factors, both genetic and environmental. A recent genome-wide association study (GWAS) of Han Chinese identified three single-nucleotide polymorphisms (SNPs rs11038167, rs11038172, and rs835784) in the tetraspanins gene TSPAN18 as possible susceptibility loci for schizophrenia. Hoping to validate these findings, we conducted a case-control study of Han Chinese with 1093 schizophrenia cases and 1022 healthy controls. Using the LDR-PCR method to genotype polymorphisms in TSPAN18, we found no significant differences (P>0.05) between patients and controls in either the allele or genotype frequency of the SNPs rs11038167 and rs11038172. We did find, however, that the frequency of the ‘A’ allele of SNP rs835784 is significantly higher in patients than in controls. We further observed a significant association (OR  = 1.197, 95%CI  = 1.047–1.369) between risk for SCZ and this ‘A’ allele. These results confirm the significant association, in Han Chinese populations, of increased SCZ risk and the variant of the TSPAN18 gene containing the ‘A’ allele of SNP rs835784.     

Association between promoter variants of interleukin-18 and schizophrenia in a Han Chinese population

An increasing amount of evidence suggests that interleukin-18 (IL-18) plays a pivotal role in the pathophysiology of schizophrenia. However, association between single nucleotide polymorphism of IL-18 and the risk of schizophrenia has not been clarified. This study examined whether two promoter polymorphisms -137 G/C (rs187238) and -607 C/A (rs1946518) of IL-18 were associated with schizophrenia and six clinical symptoms (disorder of perception, thought disorder, disturbance of emotion, disorder of behavior and volition, suicide action, and aggressive action) to provide data for screening high-risk Han Chinese individuals. Three hundred seventy-two schizophrenic patients and 353 healthy controls from a Han Chinese population were examined to assess their genotype and allele frequencies of the two promoter polymorphisms of IL-18. The genotype distributions in both patients and controls were within Hardy-Weinberg equilibrium. No significant differences were observed in the genotype or the allele frequencies of the two single-nucleotide polymorphisms between patients and controls. However, genotype frequencies of -607 C/A showed significant differences between patients and controls in the appearance of perception disorder (χ2 = 6.153, p = 0.046). A significant difference was detected in -137 G/C between patients and controls in the appearance of aggressive action (χ2 = 3.909, p = 0.048). In conclusion, IL-18 gene promoter polymorphisms may not contribute to the susceptibility of schizophrenia in a Han Chinese population, but two single-nucleotide polymorphisms, -137 G/C and -607 C/A, may play a role in the development of perception disorder and aggressive action, respectively.     

Association of the carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase gene with schizophrenia in the Chinese Han population

Several independent linkage studies have demonstrated that the 1q22 region is likely to harbor candidate schizophrenia susceptibility genes. Recently, some genetic variants within CAPON have been reported as exhibiting significant linkage disequilibrium to schizophrenia in Canadian familial-schizophrenia pedigrees. We examined nine single nucleotide polymorphisms (SNPs), which span an approximately 236-kb region of CAPON, in 664 schizophrenia cases and 941 controls in the Chinese Han population. We detected a significant difference in allele distributions of SNP rs348624 (P = 0.000017). Moreover, the overall frequency of haplotypes constructed from three SNPs including rs348624 showed significant difference between cases and controls (P = 0.000025). Our findings indicate that CAPON gene may be a candidate susceptibility gene for schizophrenia in Chinese Han population, and also provide further support for the potential importance of NMDAR-mediated glutamatergic transmission in the etiology of schizophrenia.     

RELN基因启动子区SNP位点与精神分裂症的相关性分析

目前有很多证据证明RELN基因在世界人群中是一个精神分裂症的致病基因.基于之前报道过的RELN基因在精神分裂症患者中表达下降的事实,可以推测在RELN基因启动子区可能包含影响精神分裂症发生的多态位点.该研究分析了中国西南地区病例——对照人群中(940位患者和1369位正常人)RELN基因启动子区的3个单核苷酸多态性位点与精神分裂症的相关性.研究结果显示,这些多态位点都不与精神分裂症相关,表明RELN基因的致病位点并不在其启动子区.将前人研究结果与该研究结果进行综合分析(共2843个样本),结果仍不显著.因此,该研究表明,RELN基因启动子区的单核苷酸多态性位点在中国人群中并不与精神分裂症相关.     

A Preliminary Genetic Analysis of Complement 3 Gene and Schizophrenia

Complement pathway activation was found to occur frequently in schizophrenia, and complement 3 (C3) plays a major role in this process. Previous studies have provided evidence for the possible role of C3 in the development of schizophrenia. In this study, we hypothesized that the gene encoding C3 (C3) may confer susceptibility to schizophrenia in Han Chinese. We analyzed 7 common single nucleotide polymorphisms (SNPs) of C3 in 647 schizophrenia patients and 687 healthy controls. Peripheral C3 mRNA expression level was measured in 23 drug-naïve patients with schizophrenia and 24 controls. Two SNPs (rs1047286 and rs2250656) that deviated from Hardy-Weinberg equilibrium were excluded for further analysis. Among the remaining 5 SNPs, there was no significant difference in allele and genotype frequencies between the patient and control groups. Logistic regression analysis showed no significant SNP-gender interaction in either dominant model or recessive model. There was no significant difference in the level of peripheral C3 expression between the drug-naïve schizophrenia patients and healthy controls. In conclusion, the results of this study do not support C3 as a major genetic susceptibility factor in schizophrenia. Other factors in AP may have critical roles in schizophrenia and be worthy of further investigation.     

Association of PDE4B polymorphisms and schizophrenia in Northwestern Han Chinese

The phosphodiesterase 4B (PDE4B) is a candidate susceptibility gene for schizophrenia (SCZ), interacting with DISC1, a known genetic risk factor for SCZ. To examine if variants within PDE4B gene are associated with SCZ in Northwestern Han Chinese, and if these effects vary in gender-specific subgroup, we analyzed 20 SNPs, selected from previous studies and preliminary HapMap data analyses with minor allele frequency (MAF) ≥ 20%, in a cohort of 428 cases and 572 controls from genetically independent Northwestern Han Chinese. Single SNP association, haplotype association and sex-specific association analysis were performed. We found that rs472952 is significantly associated with SCZ and rs7537440 is associated with SCZ in females. Further analysis indicated that a haplotype block spanning PDE4B2 splice site is highly associated with SCZ and several haplotypes in this block have about twofold to threefold increase in cases. Our results provide further evidence that PDE4B may play important roles in the etiology of SCZ.     

SIRT1 gene, schizophrenia and bipolar disorder in the Japanese population: an association study

Several lines of evidence suggest that alterations in circadian rhythms might be associated with the pathophysiology of psychiatric disorders such as schizophrenia and bipolar disorder (BP). A recent study reported that SIRT1 is a molecule that plays an important role in the circadian clock system. Therefore, to evaluate the association among the SIRT1 gene, schizophrenia and BP, we conducted a case-control study of Japanese population samples (1158 schizophrenia patients, 1008 BP patients and 2127 controls) with four tagging SNPs (rs12778366, rs2273773, rs4746720 and rs10997875) in the SIRT1 gene. Marker-trait association analysis was used to evaluate the allele and the genotype association with the χ(2) test, and haplotype association analysis was evaluated with a likelihood ratio test. We showed an association between rs4746720 in the SIRT1 gene and schizophrenia in the allele and the genotype analysis. However, the significance of these associations did not survive after Bonferroni's correction for multiple testing. On the other hand, the SIRT1 gene was associated with Japanese schizophrenia in a haplotype-wise analysis (global P(all markers) = 4.89 × 10(-15)). Also, four tagging SNPs in the SIRT1 gene were not associated with BP. In conclusion, the SIRT1 gene may play an important role in the pathophysiology of schizophrenia in the Japanese population.     

ABCG2基因rs2231142位点多态性与汉族女性痛风的相关性

目的：ABCG2基因第5外显子区单核苷酸多态性位点rs2231142与中国汉族男性痛风密切相关,基于痛风易感基因存在性别差异的考虑,本研究旨在探讨该单核苷酸多态性位点与中国汉族女性人群痛风易感性之间的相关性。方法：选取185例女性痛风患者和311例女性正常对照者,提取外周血基因组DNA,采用聚合酶链式反应（PCR技术）,特异性扩增ABCG2基因所需要的目的片段并测序,比较痛风组和正常对照组的基因型频率及等位基因频率分布情况。结果：rs2231142位点的CC、CA、AA基因型频率在两组间存在显著差异（x2=16.519,P〈0.001）,且痛风组中A等位基因频率显著高于正常对照组（分别为42.2%和29.3%,P〈0.001,OR 1.76[95%CI：1.35-2.31]）。结论：ABCG2基因第五外显子区rs2231142（C/A）位点的单核苷酸多态性与中国汉族女性人群痛风易感性密切相关,携带A等位基因的汉族女性人群有更高的痛风患病率。ABCG2基因首次被证实为中国汉族女性人群的痛风致病易感基因。     

基于核心家系的EGR3基因与精神分裂症的关联研究

研究表明位于染色体8p21.3区域的EGR3(Early growth response 3)是精神分裂症(Schizophrenia)的重要易感基因,然而,仍有两个病例-对照研究未能验证上述发现。为了研究EGR3基因在我国患者中是否与疾病关联,文章在中国汉族的核心家系中选择EGR3基因座位上的5个SNPs位点(rs1996147、rs1877670、rs3750192、rs35201266和rs7009708)进行基因分型和传递不平衡检验(Transmission disequilibrium test,TDT)。结果表明遗传标记rs1996147和rs3750192分别显示出显著的传递不平衡(2>4.40,P<0.05)。在连锁不平衡分析中,由2个(rs3750192和rs35201266)、3个(rs1877670、rs3750192和rs7009708)以及4个(rs1996147、rs1877670、rs3750192和rs7009708)SNPs位点构建的单倍型均显示与精神分裂症显著性关联(2>7.10,整体P<0.05)。总之,EGR3基因与中国汉族人群精神分裂症遗传易感性相关,后续关于EGR3基因进一步的功能研究将会更好的帮助我们了解该基因在疾病病理学机制中的作用。     

SLC30A8 (ZnT8) variations and type 2 diabetes in the Chinese Han population

In recent genome-wide association studies, variants in the SLC30A8 gene have been found to be associated with risk for type 2 diabetes. We examined a possible association of tag SNPs spanning SLC30A8 and their haplotypes with type 2 diabetes in the Chinese Han population. There were 1508 Chinese Han type 2 diabetes patients and 1500 age- and gender-matched control subjects; all were genotyped for three tagging SNPs (rs2466295, rs4876703, and rs11558471) of the human SLC30A8 gene. The AA genotype of rs11558471 was found significantly more frequently in type 2 diabetes patients than in controls (46 vs 24%). The frequency of the A-C-A haplotype was significantly higher in type 2 diabetes patients than in controls (0.331 vs 0.120). The frequency of the A-C-G haplotype was significantly lower in type 2 diabetes patients than in controls (0.160 vs 0.365). We conclude that type 2 diabetes is associated with the AA genotype of rs11558471 in the human SLC30A8 gene. The A-C-A haplotype appears to be a risk factor and the A-C-G haplotype may be a protective factor against type 2 diabetes in Chinese Han.     

Association Analysis of the RET Proto-Oncogene with Hirschsprung Disease in the Han Chinese Population of Southeastern China

Hirschsprung disease (HSCR) is a complex congenital disorder characterized by intestinal obstructions caused by the absence of the intestinal ganglion cells of the nerve plexuses in variable lengths of the digestive tract. This study investigated a possible role of the RET proto-oncogene in sporadic HSCR patients in the Han Chinese population. Our results indicated that rs1800858, rs1800860, rs1800863, and rs2075912, located in exons 2, 7, 15, and intron 19 of RET, are strongly associated with the disease (P < 0.01), with rs1800860 and rs1800863 playing a protective role in the pathogenesis of HSCR in the Chinese population. We also showed that the haplotype consisting of four SNPs is significantly associated with HSCR. We did not find a significant difference in the CA-repeat in intron 5 of RET between cases and controls. Our study provided further evidence that the RET gene is involved in the susceptibility to HSCR in the Han Chinese population.     

Association between ST8SIA2 and the Risk of Schizophrenia and Bipolar I Disorder across Diagnostic Boundaries

Background

Findings from family studies and recent genome-wide association studies have indicated overlap in the risk genes between schizophrenia and bipolar disorder (BD). After finding a linkage between the ST8SIA2 (ST8 alpha-N-acetyl-neuraminide alpha-2, 8-sicalyltransferase 2 gene) locus (15q26) and mixed families with schizophrenia and BD, several studies have reported a significant association between this gene and schizophrenia or BD. We investigated the genetic association between ST8SIA2 and both schizophrenia and BD in the Korean population.

Methods

A total of 582 patients with schizophrenia, 339 patients with BD, and 502 healthy controls were included. Thirty-one tag single nucleotide polymorphisms (SNPs) across the ST8SIA2 region and three other SNPs showing significant associations in previous studies were genotyped. The associations were evaluated by logistic regression analysis using additive, dominant, and recessive genetic models.

Results

Fourteen of 34 SNPs showed a nominally significant association (p < 0.05) with at least one diagnostic group. These association trends were strongest for the schizophrenia and combined schizophrenia and bipolar I disorder (BD-I) groups. The strongest association was observed in rs11637898 for schizophrenia (p = 0.0033) and BD-I (p = 0.0050) under the dominant model. The association between rs11637898 and the combined schizophrenia and BD-I group (p = 0.0006, under the dominant model) remained significant after correcting for multiple testing.

Discussion

We identified a possible role of ST8SIA2 in the common susceptibility of schizophrenia and BD-I. However, no association trend was observed for bipolar II disorder. Further efforts are needed to identify a specific phenotype associated with this gene crossing the current diagnostic categories.     

The relationship between genetic polymorphisms in apolipoprotein E (ApoE) gene and osteonecrosis of the femoral head induced by steroid in Chinese Han population

Previous studies suggested that apolipoprotein E (ApoE) genetic polymorphisms (SNPs) may result in abnormal lipid metabolism. Therefore, genetic polymorphisms in ApoE may be associated with the occurrence of osteonecrosis of the femoral head (ONFH). A case control study was designed to include 580 patients with steroid-induced ONFH and 560 age- and sex-matched non steroid-induced ONFH control subjects to analyze the association between ApoE polymorphisms and susceptibility of steroid-induced ONFH. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was utilized to differentiate two genotypes SNPs (rs7412 C/T and rs429358 T/C) in ApoE gene. Both rs7412 C/T and rs429358 T/C were found to be associated with the risk of steroid-induced ONFH. However, no significant association was observed between the haplotypes T-T, T-C and C-C in ONFH. Furthermore, T allele of rs7412 and C allele of rs429358 carriers were associated with higher levels of TG in steroid-induced ONFH patients (P?<?0.05). The study suggested that ApoE genetic polymorphisms conferred susceptibility to steroid-induced ONFH in Chinese Han population. However, the results need further investigation with large sample size and various populations.     

葡萄糖转运体9（GLUT9）基因启动子区的rs13124007（G/C）及rs6850166（G/A）位点的单核苷酸多态性（SNP）与汉族女性痛风相关性研究（英文）

目的：探讨葡萄糖转运体9（GLUT9）基因启动子区的rs13124007（C/G）及rs6850166（A/G）位点的单核苷酸多态性（SNP）与中国汉族女性人群痛风易感性之间的相关性。方法：选取185例痛风患者和300例正常对照者,提取基因组DNA,采用聚合酶链式反应（PCR技术）,特异性扩增GLUT9基因所需要的目的片段,对扩增的目的片段进行测序后,比较痛风组和正常对照组的基因型频率及等位基因频率分布情况。结果：女性痛风组中GLUT9基因的启动子区rs13124007和rs6805116两个位点的基因型频率分布与正常对照组相比,统计学上无明显的差异（X2=0.906,P=0.636;X2=3.335,P=0.189）,rs13124007 SNP位点的C等位基因频率和rs6850166SNP位点的A的等位基因频率与正常对照组相比也无明显的统计学差异（X2=0.506,P=0.477;X2=3.268,P=0.071）。结论：葡萄糖转运体9（GLUT9）基因启动子区的rs13124007（C/G）及rs6850166（A/G）位点的单核苷酸多态性（SNP）与中国汉族女性人群痛风易感性无明显的相关性。     

Association Study of N-Methyl-D-Aspartate Receptor Subunit 2B (GRIN2B) Polymorphisms and Schizophrenia Symptoms in the Han Chinese Population

Schizophrenia (SZ) is a common and complex psychiatric disorder that has a significant genetic component. The glutamatergic system is the major excitatory neurotransmitter system in the central nervous system, and is mediated by N-methyl-D-aspartate (NMDA) receptors. Disturbances in this system have been hypothesized to play a major role in SZ pathogenesis. Several studies have revealed that the NMDA receptor subunit 2B (GRIN2B) potentially associates with SZ and its psychiatric symptoms. In this study, we performed a case–control study to identify polymorphisms of the GRIN2B gene that may confer susceptibility to SZ in the Han Chinese population. Thirty-four single nucleotide polymorphisms (SNPs) were genotyped in 528 paranoid SZ patients and 528 control subjects. A significant association was observed in allele and genotype between SZ and controls at rs2098469 (χ² = 8.425 and 4.994; p = 0.025 and 0.014, respectively). Significant associations were found in the allele at rs12319804 (χ² = 4.436; p = 0.035), as well as in the genotype at rs12820037 and rs7298664 between SZ and controls (χ² = 11.162 and 38.204; p = 0.003 and 4.27×10^-8, respectively). After applying the Bonferroni correction, rs7298664 still had significant genotype associations with SZ (p = 1.71×10^-7). In addition, rs2098469 genotype and allele frequencies, and 12820037 allele frequencies were nominally associated with SZ. Three haplotypes, CGA (rs10845849—rs12319804—rs10845851), CC (rs12582848—rs7952915), and AAGAC (rs2041986—rs11055665—rs7314376—rs7297101—rs2098469), had significant differences between SZ and controls (χ² = 4.324, 4.582, and 4.492; p = 0.037, 0.032, and 0.034, respectively). In addition, three SNPs, rs2098469, rs12820037, and rs7298664, were significantly associated with cognition factors PANSS subscores in SZ (F = 16.799, 7.112, and 13.357; p = 0.000, 0.017, and 0.000, respectively). In conclusion, our study provides novel evidence for an association between GRIN2B polymorphisms and SZ susceptibility and symptoms in the Han Chinese population.     

The IL-17F sequence variant is associated with susceptibility to tuberculosis

The interleukin (IL)-17 gene plays a key role in host defence against infections from microbes, including Mycobacterium tuberculosis. Genetic factors contribute to host defence. However, whether genetic variation in IL-17 is associated with altered susceptibility to tuberculosis is unknown. A total of 596 pulmonary tuberculosis (PTB) patients, 176 extra-pulmonary tuberculosis (EPTB) patients, and 622 control patients from a Chinese Han population were recruited. Two single-nucleotide polymorphisms (SNPs) in IL-17F (rs1889570 and rs763780) and one SNP in IL-17A (rs2275913) were genotyped using the SNaPshot technique. Of the three SNPs in the IL-17 gene tested, there was an increased frequency of the rs1889570 G allele and the rs763780 C allele in the PTB patients and an increased frequency of the rs763780 C allele in the EPTB patients compared with the control patients. There were also significant differences in the distribution of the rs763780 genotype between the PTB and EPTB patients and the controls. The patients who had the CT/TT genotype of the rs763780 SNP were more susceptible to tuberculosis, compared to the CC genotype. There was no significant difference observed between the IL-17 SNPs when the PTB and EPTB patients were compared. Genetic variation in IL-17F is associated with altered susceptibility to tuberculosis and may provide valuable information in the development of tuberculosis.