Project description:Recent genetic association studies have implicated several candidate susceptibility variants for schizophrenia among general populations. Rs1344706, an intronic SNP within ZNF804A, was identified as one of the most compelling candidate risk SNPs for schizophrenia in Europeans through genome-wide association studies (GWASs) and replications as well as large-scale meta-analyses. However, in Han Chinese, the results for rs1344706 are inconsistent, and whether rs1344706 is an authentic risk SNP for schizophrenia in Han Chinese is inconclusive. Here, we conducted a systematic meta-analysis of rs1344706 with schizophrenia in Chinese population by combining all available case-control samples (N?=?12), including a total of 8,982 cases and 12,342 controls. The results of our meta-analysis were not able to confirm an association of rs1344706 A-allele with schizophrenia (p?=?0.10, odds ratio?=?1.06, 95% confidence interval?=?0.99-1.13). Such absence of association was further confirmed by the non-superiority test (p?=?0.0003), suggesting that rs1344706 is not a risk SNP for schizophrenia in Han Chinese. Detailed examinations of individual samples revealed potential sampling bias in previous replication studies in Han Chinese. The absence of rs1344706 association in Han Chinese suggest a potential genetic heterogeneity in the susceptibility of schizophrenia on this locus and also demonstrate the difficulties in replicating genome-wide association findings of schizophrenia across different ethnic populations.
Project description:Schizophrenia is one of the most serious mental diseases found in humans. Previous studies indicated that the single nucleotide polymorphism (SNP) rs1344706 in the gene ZNF804A encoding zinc finger protein 804A was associated with schizophrenia in Caucasian population but not in Chinese Han population. However, current results are conflicting in Asian population. In the present study, a meta-analysis was performed to revisit the association between rs1344706 and the risk of schizophrenia in Asian, Caucasian and other populations. Electronic search of PubMed database identified 25 case-control studies with available genotype frequencies of rs1344706 for the meta-analysis, involving a total of 15,788 cases and 22,654 controls. A pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the association. The current meta-analysis showed an association between rs1344706 and schizophrenia in Caucasian populations (P=0.028, OR=1.138, 95% CI: 1.014-1.278; P=0.004 for heterogeneity) and Asian populations (P=0.008, OR=1.092, 95% CI: 1.023-1.165; P=0.001 for heterogeneity), but not in other populations (P=0.286, OR=1.209, 95% CI: 0.853-1.714, P=0.120 for heterogeneity). Egger's test (P>0.05) and Begg's test (P>0.05) are both suggestive of the lack of publication bias for the included studies. Thus, the absence of association in other populations suggests a genetic heterogeneity in the susceptibility of schizophrenia and demonstrates the difficulties in replicating genome-wide association study findings regarding schizophrenia across different ethnic populations. To validate the association between rs1344706 and schizophrenia, further studies with larger participant populations worldwide are needed.
Project description:The rs1344706, an intronic SNP within the zinc-finger protein 804A gene (ZNF804A), was identified as one of the most compelling risk SNPs for schizophrenia (SZ) and bipolar disorder (BD). It is however not clear by which molecular mechanisms ZNF804A increases disease risk. We evaluated the role of ZNF804A in SZ and BD by genotyping the originally associated rs1344706 SNP and an exonic SNP (rs12476147) located in exon four of ZNF804A in a sample of 422 SZ, 382 BD, and 507 controls from the isolated population of the Costa Rica Central Valley. We also investigated the rs1344706 SNP for allelic specific expression (ASE) imbalance in the dorsolateral prefrontal cortex (DLPFC) of 46 heterozygous postmortem brains. While no significant association between rs1344706 and SZ or BD was observed in the Costa Rica sample, we observed an increased risk of SZ for the minor allele (A) of the exonic rs12476147 SNP (p=0.026). Our ASE assay detected a significant over-expression of the rs12476147 A allele in DLPFC of rs1344706 heterozygous subjects. Interestingly, cDNA allele ratios were significantly different according to the intronic rs1344706 genotypes (p-value=0.03), with the rs1344706 A allele associated with increased ZNF804A rs12476147 A allele expression (average 1.06, p-value=0.02, for heterozygous subjects vs. genomic DNA). In conclusion, we have demonstrated a significant association of rs12476147 with SZ, and using a powerful within-subject design, an allelic expression imbalance of ZNF804A exonic SNP rs12476147 in the DLPFC. Although this data does not preclude the possibility of other functional variants in ZNF804A, it provides evidence that the rs1344706 SZ risk allele is the cis-regulatory variant directly responsible for this allelic expression imbalance in adult cortex.
Project description:Abstract Background: Following both meta-analysis and extensive resequencing, the single-nucleotide polymorphism of allele A, rs1344706, located in intron 2 of the zinc-finger protein gene ZNF804A, continues to be the common variant most strongly associated with schizophrenia risk (P = 1.1_10–13). ZNF804a is highly expressed in adult brain and functional effects on both protein expression, and altered DNA–protein interaction have been reported. In addition, the ZNF804A rs1344706 A allele has recently been reported to be associated with worse clinical outcome. We were interested in examining whether another proxy for worse clinical outcome, the Positive and Negative Syndrome Scale (PANSS) excitement factor, is associated with a ZNF804a genotype. We hypothesized that a single-nucleotide polymorphism in ZNF804a could be associated with impulsivity. The aim of this study was to assess the association of a single-nucleotide polymorphism rs1344706 with the PANSS excitement factor. Methods: We tested the effect of rs1344706 (A/C) genotype in 133 individuals with DSM-5 chronic schizophrenia using the PANSS. Scores on the PANSS excitement factor were compared between individuals who expressed allele A and those who expressed allele C (individuals with the heterogeneous allele A/C were combined to the C group). General Linear Model (GLM) was used to analyze the differences between groups for the PANSS Excitement Factor (assessed by the summation of: excitement, hostility, uncooperativeness, and poor impulse control). Results: A total of 133 subjects were sampled for ZNF804; however, PANSS data were available for 122 subjects. Of the 122, 68.85% (n = 84) of subjects presented with allele A and 31.15% (n = 38) with allele C. In all, 67.85% (n = 57) of the individuals with allele A were African Americans, and 28.95% (n = 11) of individuals with allele C were African Americans, and 39.47% (n = 15) were Hispanics. The PANSS total score for the entire sample was 72.64 (SD = 9.33). PANSS excitement factor scores ranged from 4 to 15 in group A and 4 to 14 in group C. GLM analysis showed a significant difference in ZNF804, F(1, 121) = 5.595, P = .020, between individuals with allele A compared to those with allele C. The mean excitement factor score for allele A was lower (mean = 7.762, SE = 0.273) than for allele C group (mean = 8.921, SE = 0.427). Conclusion: While the risk “A” allele at rs1344706 has been associated with altered functional brain connectivity and represents a risk factor for psychosis, our results shows an association of the “C” allele at rs1344706 with impulsivity in chronic schizophrenia patients. The difference in our findings when compared to previous reports may have to do with the differing ethnic distribution of our population, which is predominantly African American. This finding could be of nosological value for biological subtyping across the spectrum of schizophrenia, although important limitations should be noted such as small sample size and lack of ethnic diversity of our population.
Project description:Objective: Schizophrenia is known as a severe mental disorder worldwide. Genome-wide association studies have revealed that rs1344706, located in ZNF804A, is a risk variant for schizophrenia among various populations. The current study was conducted to find correlation between rs1344706 polymorphism and schizophrenia in East of Iran. Method: This case-control study assessed 150 schizophrenia cases as well as 150 healthy controls. The single nucleotide polymorphism (SNP) was genotyped using the Tetra-Amplification Refractory Mutation System-Polymerase Chain Reaction (Tetra-ARMS-PCR) method. Analyses based on the Chi-square test and logistic regression were calculated by SPSS. Results: The TT, GT, and GG genotype frequencies at rs1344706 in schizophrenia cases were 48.0%, 40.0%, and 12.0%, whereas in controls, they were 49.3 %, 36.7 %, and 14.0 %, respectively. The T and G allele frequencies were 68 % and 32 % in cases and 67 % and 33 % in healthy controls. The results of logistic regression indicated that there is no association between rs1344706 alleles (P = 1.000) and genotypes (P = 0.647 for GT and P = 0.726 for GG) with susceptibility to schizophrenia. Conclusion: Overall, there was no significant relationship between rs1344706 SNP and schizophrenia in Iran's Eastern population. However, further research focusing on more SNPs of ZNF804A and larger samples in other ethnicities is necessary to confirm these results.
Project description:Rs1344706 in the the zinc finger protein 804A (ZNF804A) gene has been identified to be associated with schizophrenia and bipolar disorder (BD) in Europeans. However, whether rs1344706 is associated with schizophrenia in Chinese populations remains inconclusive; furthermore, the association between rs1344706 and BD in Chinese populations has been rarely explored. To explore the association between rs1344706 and schizophrenia/BD in Chinese populations, we genotyped rs1344706 among 1128 Chinese subjects (537 patients with BD and 591 controls) and found that rs1344706 showed marginal allelic association with BD (P = 0.028) with T-allele being more prevalent in cases than that in controls (OR = 1.19, 95% CI 1.03-1.37). Meta-analysis of rs1344706 by pooling all available data showed that rs1344706 was significantly associated with BD (P = 0.001). Besides, positive association of rs1344706 with schizophrenia was observed in Northern Chinese (P = 0.005). Furthermore, ZNF804A is highly expressed in human and mouse brains, especially in prenatal stage.
Project description:Altered brain connectivity has been widely considered as a genetic risk mechanism for schizophrenia. Of the many susceptibility genes identified so far, ZNF804A (rs1344706) is the first common genetic variant associated with schizophrenia on a genome-wide level. Previous fMRI studies have found that carriers of rs1344706 exhibit altered functional connectivity. However, the relationship between ZNF804A and white matter structural connectivity in patients of schizophrenia remains unknown. In this study, 100 patients with schizophrenia and 69 healthy controls were genotyped at the single nucleotide polymorphism rs1344706. Diffusion tensor imaging (DTI) was conducted and analyzed with tract-based spatial statistics. Systematic statistical analysis was conducted on multiple diffusion indices, including fractional anisotropy, axial diffusivity, radial diffusivity, and mean diffusivity. Unpaired two-sample t-test revealed significant differences in fractional anisotropy and diffusivity between schizophrenia and control groups. A two-way ANOVA analysis was conducted to assess the main effects of and the interaction between schizophrenia and ZNF804A. Although significant main effects of the diagnosis of schizophrenia were found on radial diffusivity, no association between the ZNF804A (rs1344706) and white matter connectivity was found in the entire group of subjects or in a selected subgroup of age-matched subjects (n=72).
Project description:Using the relative expression levels of two SNP alleles of a gene in the same sample is an effective approach for identifying cis-acting regulatory SNPs (rSNPs). In the current study, we established a process for systematic screening for cis-acting rSNPs using experimental detection of AI as an initial approach. We selected 160 expressed candidate genes that are involved in cancer and anticancer drug resistance for analysis of AI in a panel of cell lines that represent different types of cancers and have been well characterized for their response patterns against anticancer drugs. Of these genes, 60 contained heterozygous SNPs in their coding regions, and 41 of the genes displayed imbalanced expression of the two cSNP alleles. Genes that displayed AI were subjected to bioinformatics-assisted identification of rSNPs that alter the strength of transcription factor binding. rSNPs in 15 genes were subjected to electrophoretic mobility shift assay, and in eight of these genes (APC, BCL2, CCND2, MLH1, PARP1, SLIT2, YES1, XRCC1) we identified differential protein binding from a nuclear extract between the SNP alleles. The screening process allowed us to zoom in from 160 candidate genes to eight genes that may contain functional rSNPs in their promoter regions.
Project description:Objective: Alcohol use disorder (AUD) is the most common substance use disorder, which may relate to increased impulsivity. A more detailed understanding of the potential moderating factor on association between AUD and impulsivity is likely to have far-reaching effects. This study aims to examine whether the interaction between a genetic variant ZNF804A rs1344706 and alcohol use is related to impulsivity in Chinese Han adult males diagnosed with AUD. Methods: A total of 455 Chinese Han adult males diagnosed with AUD were included in this study. Impulsivity was assessed using Barratt Impulsiveness Scale. Alcohol dependence was measured by Michigan Alcoholism Screening Test. Genomic DNA was extracted from peripheral blood of participants and genotyped. Results: Hierarchical multiple regression yielded a significant interaction between ZNF804A rs1344706 and alcohol use (β = 0.20, p = 0.0237). Then, A region of significance (RoS) test was performed to interpret the interaction effect. Re-parameterized regression models revealed that the interaction between ZNF804A rs1344706 and alcohol problem severity fit to the weak diathesis-stress model (R 2 = 0.15, p < 0.0010), indicating that the T allele carriers are more susceptible to alcohol problem severity, jointly contributing to impulsivity. Conclusions: This study, which analyzed a specific gene-environment interaction, demonstrated that carriers of the T allele of ZNF804A rs1344706 may be more susceptible to alcohol problem severity, correlated with higher levels of impulsivity during withdrawal.