ABSTRACT
Objective: To investigate the correlation between the polymorphisms of locus in the promoter region of glutamate decarboxylase 1 (GAD1) gene and γ-aminobutyric acid (GABA)A receptor β-3 gene (GABRB3) and schizophrenia (SZ) in Chinese Han population. Methods: SNaPshot genotyping technique was used to detect the polymorphisms of rs3791878 and rs3749034 in the promoter region of GAD1 and rs4906902 in the promoter region of GABRB3 in 545 SZ patients (case group) and 624 healthy controls (control group). The distribution of alleles and genotypes under different genetic models between the case group and the control group in all samples were compared by SNPstats online software. The above analysis was also performed after the subjects were stratified according to gender. The correlation of G/T risk genotype of rs3791878 with the age of the first onset of male SZ was investigated by survival analysis. Results: Under over-dominant genetic model, the distribution of G/T risk genotype of rs3791878 showed statistically difference between the male SZ cases and male controls (P=0.000), and the difference was still statistically significant after Bonferroni correction (P=0.000). However, there was no significant difference in the distribution of alleles and genotypes under different genetic models of rs3749034 and rs4906902 between the case group and the control group in all samples (P>0.05), and there was also no significant difference in the distribution of alleles between the case group and the control group after them being stratified according to gender (P>0.05). Kaplan-Meier analysis showed that there was no significant difference between the age of onset of male SZ who carried G/T genotype in rs3791878 locus and that of male SZ who did not carry it (P=0.603). Conclusion: The polymorphism of rs3791878 in the promoter region of GAD1 is significantly associated with the incidence of male SZ in Chinese Han population.
ABSTRACT
Objective To investigate gene-gene interactions of suicidal behavior with single-nucleotide-polymorphism (SNP) in MAOA ,GAD1 and 5-HTR2C by multifactor dimensionality reduction .Methods For this case-control study ,six SNPs were captured in related genes and detected in blood samples obtained from 21 patients with suicidal behavior and 50 healthy individuals .The genotype frequency and allele frequency as well as the Hardy-Weinberg equilibrium (HWE) ,tests were performed and compared by plink software .The gene-gene interactions models were built by the MDR software .Results The HWE test for case group showed that rs3813928 rs518147 of 5-HTR2C gene was not in line with HWE ( P< 0 .05) .However ,the additive model analysis after adjustment by gender indicated that the polymorphism had a positive correlation with suicidal behavior in case group .The case and control groups differed significantly only in genotype frequencies of 5-HTR2C gene (χ2 =6 .18 , P=0 .04) .There was no significant difference in allele and genotype frequencies of the other genes ( P>0 .05) .The best combination model of MDR was rs5953210-rs769391 OR=20 .19 ,95% CI 4 .19-97 .38 , P<0 .01 ,with significant interaction . Conclusion The 5-HTR2C gene rs3813928 and rs518147 polymorphisms may play an important role in the susceptibility to suicidal behavior .The combination of MAOA with GAD1 has a significant interaction which may increase the risk of suicidal behavior .