| Background and purpose:Schizophrenia(SZ) is a complex variety of behavioral and cognitive syndrome, the disease is mainly due to genetic factors or environmental factors during the development of the brain damage caused. It is a cause of severe mental illness is not yet clear, and there is often occurs in young adults, the incidence of slow or subacute, easy to relapse. The disease in the clinical manifestations of behavioral and cognitive disorders and abnormal mental activity, known in feeling, emotional aspects often shows inconsistent. In China, the incidence rate of 0.6% to 1.2%, this being hospitalized for more than 50% of the total number of patients hospitalized. Schizophrenia phenotype often has diversified non-uniformity, a number of minor gene regulation, combined with environmental factors, the heritability of 64%-80%.Currently, scholars believe that the main obstacle to the neurotransmitter dopamine is the origin of mental illness, but there is extensive evidence that mutations in a number of brain regions and neural circuits is one of the causes of mental illness. Interfere with synaptic function may be due to abnormalities caused by neural connections, this process also involves the nature of the intermediate neurons, the location and the occurrence of some of the uncertainty and the like. Studies have shown that NCAN gene, a human megakaryocytic leukemia factor 1(MKL1) gene and synaptic plasticity and growth are related. NCAN gene is widely expressed in the hippocampus and cerebral cortex, especially the prefrontal cortex, these organizations for human cognition, feeling them play an important role in nerve tissue. MKL1 gene is widely distributed in the trigeminal ganglia, the assembly of neurons migrate from the regulation. Meanwhile, MKL1 or SRF cofactors, the regulation of dendritic growth, and regulation of signal transduction in neurons. Catechol-O-methyltransferase(COMT) is a dopamine-degrading enzyme pathway which is mainly distributed in the central nervous system which, from the transfer of the regulation of nerve signals can be adjusted dopamine, epinephrine, norepinephrine metabolism. NCAN gene research in recent years is that the gene mutation causes abnormal neuron damage the hippocampus, so as to affect the central nervous system. MKL1 mutation often leads to dendritic elongation not affect nerve adhesion. COMT is the focus of the study of mental diseases, COMT mutation often causes brain disorders, cognitive problems, many studies have shown that this gene is a susceptibility gene for schizophrenia, but its impact mechanism remains to be studied. At present, the domestic research on COMT gene is more, and have different results, and NCAN, MKL1 gene restricted to European research reports.In order to explore NCAN gene, MKL1 gene association COMT gene polymorphism and schizophrenia occurred in henan, this study selected NCAN gene rs1064395 locus, MKL1 gene rs6001946 locus, rs165774 COMT gene locus, and used multi-restriction fragment length state polymerase chain reaction(PCR-RFLP) method to research 3 gene locus in Henan Han people with genotype frequencies and allele frequency analysis. And according to the difference of different gender stratification analysis, using the genetic model and linkage disequilibrium analysis method to study the interaction of three-gene three points. So as to investigate the influence of these three genes three points for Henan Han schizophrenia patient. Materials and Methods:The case study group of 308 cases(177 men and 131 women; mean age: 37.7 ± 12.4 years), all from October 2010 to April 2014 in Zhengzhou City, Henan Province Psychiatric Hospital, Luoyang City-Kang Hospital Schizophrenia hospitalized patients, are in line with Chinese mental disorders classification and diagnostic criteria Third Edition(CCMD-3) and the American mental disorders fourth edition of the diagnostic and statistical Manual(DSM-Ⅳ) diagnostic criteria, disease and schizophrenia positive and negative syndrome scale( PANSS) score> 45 points. Exclude the diagnosis is unknown, is brain matter lesions, nerve growth retardation, seizures, liver and kidney dysfunction, severe malnutrition and other patients; exclude alcohol dependence, other psychotropic substance abusers and the like.A control group of 361(217 male and 144 female; mean age: 36.2 ± 11.6 years) selected from the same period in Henan unrelated healthy individuals were randomly excluded family has mental illness or suicide. Age and sex between case and control groups were not significantly different distributions(t = 1.56, P> 0.05; χ2 = 0.48, P> 0.05).Subjects were all agreed by himself or guardian consent.This research method using PCR-RLFP: 1) collection of cases and controls peripheral blood, EDTA anticoagulant agent, standard phenol- chloroform extraction of whole genome DNA, ultra trace concentration and purity of nucleic acid protein analyzer test sample of DNA; 2) primers designed and synthesized, PCR amplification of the target gene; 3) using restriction endonucleases specific to split PCR product; 4) using DNA fragments separated on 2% agarose gel electrophoresis after digestion, then the use of ultraviolet imaging pictures and record-keeping system, and the results of genotype analysis; 5) select the product you point different genotypes of PCR for DNA sequencing.Use software HWE 1.20 Hardy-Weinberg equilibrium test; using SPSS17.0 statistical analysis software to analysis the different genotypes, alleles and genetic models, and calculate the odds ratio(OR) and 95% confidence intervals(95% CI);we also used this software to analyze the different genotype and allele distribution of gender.Our study make use of SHEsis online software for haplotype analysis. Gene and gene interactions by multifactor dimensionality reduction(MDR) analysis is completed.Result:1.The distribution frequency of rs1064395 loci, rs6001946 locus, rs165774 locus for case and control groups genotypes were consistent in Hardy-Weinberg equilibrium(P values were 0.067 and 0.093,0.086 and 0.981,0.660 and 0.711, respectively). 2. In the dominant model,NCAN gene rs1064395 locus was statistically significant differences in genotype distribution between case and control group(χ2=11.93,P<0.0167), there are significant differences between the two groups in the additive model genotypes(χ2=7.67,P<0.0167).MKL1 gene locus rs6001946 AG genotype was statistically significant differences in case group and the control group(χ2 = 12.30, P <0.0167), the relative risk analysis showed that AG genotype was a schizophrenia susceptibility factor. COMT gene rs165774 loci GA genotype distribution was statistically significant differences in case group and the control group(χ2 =6.170, P <0.0167). The relative risk analysis showed that GA genotype was a schizophrenia susceptibility factor. 3. Gender stratified analysis showed that GA genotype of NCAN gene rs1064395 was higher susceptibility to schizophrenia(χ2 = 8.90, P <0.0167)in the male Henan Han population. AG genotype of MKL1 gene rs6001946 was a susceptibility risk factor in the male Henan Han populaiong(χ2 = 12.55, P <0.0167). AA, GA genotypes of COMT gene rs165774 were higher susceptibility to schizophrenia(χ2 = 7.67, P <0.0167; χ2 = 6.92, P <0.0167). 4.In the three genes interaction model, one-factor and three-factor model was statistically significant(P = 0.001), in which the three-factor model cross-validation consistency 10/10. And the three-factor test sample accuracy was the highest(60.35%). Therefore, three-factor model for the best model. System interaction tree also showed the Presence of three-Point interaction.Conclusion:1. A allele of NCAN gene locus rs1064395,G allele of MKL1 gene locus rs6001946 and A allele of COMT gene locus rs165774 are potential risk factors for schizophrenia in Henan Han population. 2. Men in Henan Han population, rs1064395 NCAN gene loci GA genotype individuals, rs6001946 MKL1 gene loci AG genotype individuals and rs165774 COMT gene loci GA genotype individuals with schizophrenia susceptibility are relatively higher. 3.There is an interaction among the NCAN gene, the MKL1 gene and the COMT gene in the pathogenesis of schizophrenia in Henan Han population. |
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