Comprehensive functional annotation of susceptibility SNPs prioritized 10 genes for schizophrenia
TRANSLATIONAL PSYCHIATRY
Authors: Niu, Hui-Min; Yang, Ping; Chen, Huan-Huan; Hao, Ruo-Han; Dong, Shan-Shan; Yao, Shi; Chen, Xiao-Feng; Yan, Han; Zhang, Yu-Jie; Chen, Yi-Xiao; Jiang, Feng; Yang, Tie-Lin; Guo, Yan
Abstract
Nearly 95% of susceptibility SNPs identified by genome-wide association studies (GWASs) are located in non-coding regions, which causes a lot of difficulty in deciphering their biological functions on disease pathogenesis. Here, we aimed to conduct a comprehensive functional annotation for all the schizophrenia susceptibility loci obtained from GWASs. Considering varieties of epigenomic regulatory elements, we annotated all 22,688 acquired susceptibility SNPs according to their genomic positions to obtain functional SNPs. The comprehensive annotation indicated that these functional SNPs are broadly involved in diverse biological processes. Histone modification enrichment showed that H3K27ac, H3K36me3, H3K4me1, and H3K4me3 were related to the development of schizophrenia. Transcription factors (TFs) prediction, methylation quantitative trait loci (meQTL) analyses, expression quantitative trait loci (eQTL) analyses, and proteomic quantitative trait loci analyses (pQTL) identified 447 target protein-coding genes. Subsequently, differential expression analyses between schizophrenia cases and controls, nervous system phenotypes from mouse models, and protein-protein interaction with known schizophrenia-related pathways and genes were carried out with our target genes. We finaly prioritized 10 target genes for schizophrenia (CACNA1C, CLU, CSNK2B, GABBR1, GRIN2A, MAPK3, NOTCH4, SRR, TNF, and SYNGAP1). Our results may serve as an encyclopedia of schizophrenia susceptibility SNPs and offer holistic guides for post-GWAS functional experiments.
Is variation in the GABA(B) receptor 1 gene associated with temporal lobe epilepsy ?
EPILEPSIA
Authors: Tan, NCK; Heron, SE; Scheffer, IE; Berkovic, SF; Mulley, JC
Abstract
Purpose:gamma-Aminobutyric acid (GABA)-receptor genes are prime candidates for a role in seizure susceptibility. An association between the c.1465G -> A variant in the GABA(B) receptor 1 gene (GABBR1) and susceptibility to temporal lobe epilepsy (TLE) has been reported in an Italian cohort. We sought to replicate this association in an independent Australian cohort. Methods: The 234 patients with TLE and 164 healthy controls were genotyped for the c.1465G -> A variant, by using inclusion criteria identical to those of the first study. Results: The c.1465G -> A variant was found in one TLE patient and one control subject. Genotype and allele frequencies did not differ between groups. Conclusions: We did not replicate the reported associations between the c.1465G -> A variant and susceptibility to TLE. We suggest that the initial positive association may be due to undetected population stratification; the importance of genomic control is emphasized. Population-specific effects also may play a role, and we highlight the need to demonstrate an in vitro functional effect to give biologic meaning to any proposed association.