The Association Between The Polymorphisms Of HTR3D Gene With The Risk Of Schizophrenia And The Forensic Significance

Objective: Schizophrenia is a common neurological chronic disorder whose etiology remains uncertain,but it's widely believed that complex genetic and environmental factors contributed to the pathogenesis and exacerbation of the disorder presently.Schizophrenia have caused heavy burden to patients and their families and society.However,in the current practice of forensic psychiatry appraisal,relatively objective indexes are still deficient.The current studies have indicated that the polymorphisms of gene HTR3 D might related to the pathophysiology of schizophrenia.Presently,the studies about the polymorphisms of HTR3 D in the northern Chinese Han population are relatively deficient and the investigations about HTR3 D and the risk of schizophrenia remain poor at home and abroad.This study was conducted to explore the associations between polymorphisms of HTR3 D with the occurrence of schizophrenia in the northern Chinese Han population.Methods: We conducted a case-control study including 269 schizophrenic patients(134 males,135 females)and 286 healthy unrelated individuals(125 males,161 females)in the northern Han Chinese subjects.After collecting their blood samples from vein,DNA samples were extracted and target fragments were amplified by PCR,and target loci were genotyped by Sanger DNA sequencing.We analyzed the differences between groups of allele,genotype and haplotype frequencies in several variants by statistical methods in order to investigate the associations between the polymorphisms of these variants with the risk of schizophrenia.What's more,we calculated the forensic parameters of each variants and the haplotype composed of these variants.Results: A total of six variants were discussed in our study.One locus was in the exon region(rs6789754)and the other five were in the 3'UTR(rs6765152,rs6789882,rs6789682,rs66883074 and rs55953689).No significant statistical discrepancy was observed between case and control groups in these six variants(P>0.05).For haplotype analysis,there were a total of five main haplotypes whose frequencies were above 5% composed by these six variants,which accounted for more than 95% totally in both case and control groups,and there was no statistical significance both between case and control groups and between gender after Bonferroni correction(P>0.05/5).We also found that some genetic markers,SNP rs6789754,rs6789682,rs55953689 and the haplotype composed of the six variants,had good powers of individual identification: the powers of discrimination of these genetic markers were 0.528,0.589,0.572 and 0.872 respectively,and their powers of exclusion were 0.097,0.223,0.133 and 0.501 respectively.Conclusion: Our study indicated that the polymorphisms of variants so well as haplotypes composed of these variants in HTR3 D gene were not associated with the risk of schizophrenia in the northern Chinese Han population.