Association Of Genetic Polymorphism Of GABRG2 Gene 3? Region With Schizophrenia And Its Forensic Significance

Objective: At present,there were few studies on the polymorphism of GABRG2 gene in Northern Chinese Han population,and the correlation between these polymorphisms and schizophrenia were also rare.In the current forensic expertise,especially for forensic psychiatric identification,it was generally based on the diagnostic criteria of clinical psychiatry,through the identification of the identified person's mental activity and other characteristics of the relevant examination to judge whether there is mental illness or not.However,due to the lack of objective biological indicators,which leads to the diagnosis of mental illness was more affected by individual subjective consciousness and also affect the real validity of the identification results.The purpose of this study was to explore the correlation between the genetic polymorphism of GABRG2 gene 3? region and schizophrenia in the northern Han population and its forensic significance,so as to provide genetic basis for forensic psychiatric identification.Methods: The samples of this study included 213 unrelated healthy individuals and 206 patients with schizophrenia in Northern Chinese Han population.The venous blood samples were collected and genomic DNA was extracted.The target fragment was amplified by PCR,and the sequence information of the amplified product was obtained by Sanger sequencing.In terms of data processing,we chose SPSS version 22.0 to calculate the superiority over(OR)and 95% confidence interval(CIs),and used Haploview v4.2 software to test Hardy-Weinberg balance and predict haplotypes.We used chi-square test to calculate the correlation of schizophrenia and these alleles,genotypes and haplotypes.In addition,the forensic parameters of various variation sites and main haplotypes were calculated by Power Stats v1.2.Results: In this study,partial loci were detected in the 3? regulatory region of the GABRG2 gene in samples from the northern Han Chinese subjects: rs418210(C/T),rs424740(T/A),rs34705786(AT/..),rs401750(C/T)and rs647625(G/A).The genotypic distribution of the five loci in the control group was consistent with Hardy-Weinberg equilibrium.There was no significant difference in the frequency distribution of alleles and genotypes between the case group and the control group(P > 0.05).There was no significant difference in the distribution of six haplotypes between the case group and the control group and between the sexes(P > 0.05).The personal recognition probability of five loci is between 0.613 and 0.634,and the non-paternal exclusion rate is between 0.178 and 0.187.The individual identification probabilities of haplotype TAd TA and CTi CG were 0.493 and 0.467 respectively,and the non-paternal exclusion probabilities were 0.185 and 0.179 respectively.Conclusion: Our study indicated that the genetic polymorphisms of neither above loci(rs418210,rs424740,rs34705786,rs401750 and rs647625)nor haplotypes composed by these loci in GABRG2 gene were not associated with schizophrenia in the northern Chinese Han population.These loci and haplotypes have good genetic polymorphism and high identification ability,which can provide potential genetic markers for personal identification and paternity testing in forensic evidence.