Résumé
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.
Résumé
OBJECTIVES: The studies on the genetic risk factors of the children of alcoholics (COAs) are still in an early stage. The A 1 allele of the dopamine receptor 2 gene (DRD2) may be associated with the negative affect and positive alcohol expectancy of the COAs. In addition, several researchers reported that COAs might be associated with the GABAA receptor beta subunit gene (GABRB3) and serotonin transporter gene (5-HTTLPR). In this study, we investigated the association of polymorphism of the DRD2, Dopamine D4 receptor gene (DRD4), GABRB3, 5-HTTLPR with COAs to examine the genetic risk factors of COAs. METHODS: Twenty-two COAs and 23 control children (children of non-Alcoholics ; Non-COAs) were included for the genetic study. All COAs aged 6 to 18 were recruited and selected from families of alcoholic patients in alcohol clinics of three university and mental hospital. Alcoholism of parents was classified as type I (non-antisocial, late onset) and type II (antisocial, early onset) by Cloninger's classification. The genotyping of the DRD2, DRD4, GABRB3, 5-HTTLPR was carried out. Chi-square method was used for evaluating the associations between genetic polymorphism and the COAs. RESULTS: The frequency of A1+ allele of DRD2 in COAs were significantly higher than Non-COAs (Chi-square=4.45, df=1, p=0.035). Significant association between the genotype of DRD4 and COAs was found (Chi-square=8.32, df=1, p=0.004). G1- alleles of GABRB3 in COAs were significantly higher than in Non-COAs (Chi-square=6.622, df=1, p=0.022). We found no association of the polymorphic alleles of 5-HTTLPR with the COAs (Chi-square=0.021, df=1, p=0.884). There were significant associations between the type of parental alcoholism and depression of COAs. CONCLUSION: We found that the children of alcoholics had significantly increased genetic risk of alcohol drinking expectancy. This study provides some preliminary information on the risk and protective factors associated with the COAs, which can be used as a foundation for prevention and intervention of future psychopathology.