1Biol. Psychiatry 2008 Nov 64: 789-96
PMID18571626
TitleRASD2, MYH9, and CACNG2 genes at chromosome 22q12 associated with the subgroup of schizophrenia with non-deficit in sustained attention and executive function.
AbstractIn a previous linkage study of schizophrenia that included Taiwanese samples, the marker D22S278 (22q12.3) was significantly linked to schizophrenia (p = .001).
We conducted fine mapping of the implicated genomic region, with 47 validated single nucleotide polymorphism (SNP) markers around 1 Mb of D22S278, in a Taiwanese sample of 218 pedigrees with at least 2 siblings affected with schizophrenia. We examined the association of these SNPs and their haplotypes with schizophrenia and with subgroups defined by the presence and absence of deficits in sustained attention as assessed by undegraded and degraded continuous performance tests (CPTs). We also examined subgroups defined by deficits in categories achieved in the Wisconsin Card Sort Test (WCST).
Three of five candidate vulnerability genes (RASD2, APOL5, MYH9, EIF3S7, and CACNG2), which had marginally significant associations with schizophrenia, had significant associations with schizophrenic patients who did not have deficits in sustained attention on the undegraded CPT (RASD2 gene SNP rs736212; p = .0008 with single locus analysis) and the degraded CPT (MYH9 gene haplotype 1-1-1-1 of SNP rs3752463 - rs1557540 - rs713839 - rs739097; p = .0059 with haplotype analysis). We also found a significant association for patients who showed no deficits in executive function as measured by categories achieved in the WCST (CACNG2 gene haplotype 2-1-1-1 of SNP rs2267360 - rs140526 - rs1883987 - rs916269; p = .0163 with haplotype analysis).
The genes RASD2, MYH9, and CACNG2 might be vulnerability genes for neuropsychologically defined subgroups of schizophrenic patients.
SCZ Keywordsschizophrenia, schizophrenic
2Biol. Psychiatry 2008 Nov 64: 789-96
PMID18571626
TitleRASD2, MYH9, and CACNG2 genes at chromosome 22q12 associated with the subgroup of schizophrenia with non-deficit in sustained attention and executive function.
AbstractIn a previous linkage study of schizophrenia that included Taiwanese samples, the marker D22S278 (22q12.3) was significantly linked to schizophrenia (p = .001).
We conducted fine mapping of the implicated genomic region, with 47 validated single nucleotide polymorphism (SNP) markers around 1 Mb of D22S278, in a Taiwanese sample of 218 pedigrees with at least 2 siblings affected with schizophrenia. We examined the association of these SNPs and their haplotypes with schizophrenia and with subgroups defined by the presence and absence of deficits in sustained attention as assessed by undegraded and degraded continuous performance tests (CPTs). We also examined subgroups defined by deficits in categories achieved in the Wisconsin Card Sort Test (WCST).
Three of five candidate vulnerability genes (RASD2, APOL5, MYH9, EIF3S7, and CACNG2), which had marginally significant associations with schizophrenia, had significant associations with schizophrenic patients who did not have deficits in sustained attention on the undegraded CPT (RASD2 gene SNP rs736212; p = .0008 with single locus analysis) and the degraded CPT (MYH9 gene haplotype 1-1-1-1 of SNP rs3752463 - rs1557540 - rs713839 - rs739097; p = .0059 with haplotype analysis). We also found a significant association for patients who showed no deficits in executive function as measured by categories achieved in the WCST (CACNG2 gene haplotype 2-1-1-1 of SNP rs2267360 - rs140526 - rs1883987 - rs916269; p = .0163 with haplotype analysis).
The genes RASD2, MYH9, and CACNG2 might be vulnerability genes for neuropsychologically defined subgroups of schizophrenic patients.
SCZ Keywordsschizophrenia, schizophrenic
3Schizophr. Res. 2010 May 118: 106-12
PMID20188514
TitleFailure to find an association between myosin heavy chain 9, non-muscle (MYH9) and schizophrenia: a three-stage case-control association study.
AbstractSeveral genome-wide linkage studies have suggested linkage between markers on the long arm of chromosome 22 and schizophrenia. It has also been reported that 22q11.2 deletions increase the risk of schizophrenia. Therefore, 22q is a candidate region for schizophrenia. To search for genetic susceptibility loci for schizophrenia on 22q, we conducted a three-stage case-control association study in Japanese individuals. In the first stage, we examined 13 microsatellite markers on 22q in 766 individuals (340 patients with schizophrenia and 426 control individuals) and found a potential association of AFM262VH5 (D22S283) with schizophrenia. In the second stage, we performed fine mapping of the myosin heavy chain 9, non-muscle (MYH9) gene, where AFM262VH5 is located, using 25 tagging single nucleotide polymorphisms (SNPs). We obtained potential associations between three SNPs in MYH9 and schizophrenia in 1193 individuals (595 patients and 598 controls), which included the individuals analyzed in the first stage. In the third stage, however, we could not replicate these associations in 4694 independent individuals (2288 patients and 2406 controls). Our results suggest that MYH9 does not confer increased susceptibility to schizophrenia in the Japanese population, although we could not exclude possible contributions of other genes on 22q to the pathogenesis of schizophrenia.
SCZ Keywordsschizophrenia, schizophrenic
4PLoS ONE 2015 -1 10: e0133404
PMID26193471
TitleNetwork-Based Analysis of Schizophrenia Genome-Wide Association Data to Detect the Joint Functional Association Signals.
Abstractschizophrenia is a common psychiatric disorder with high heritability and complex genetic architecture. Genome-wide association studies (GWAS) have identified several significant loci associated with schizophrenia. However, the explained heritability is still low. Growing evidence has shown schizophrenia is attributable to multiple genes with moderate effects. In-depth mining and integration of GWAS data is urgently expected to uncover disease-related gene combination patterns. Network-based analysis is a promising strategy to better interpret GWAS to identify disease-related network modules. We performed a network-based analysis on three independent schizophrenia GWASs by using a refined analysis framework, which included a more accurate gene P-value calculation, dynamic network module searching algorithm and detailed functional analysis for the obtained modules genes. The result generated 79 modules including 238 genes, which form a highly connected subnetwork with more statistical significance than expected by chance. The result validated several reported disease genes, such as MAD1L1, MCC, SDCCAG8, VAT1L, MAPK14, MYH9 and FXYD6, and also obtained several novel candidate genes and gene-gene interactions. Pathway enrichment analysis of the module genes suggested they were enriched in several neural and immune system related pathways/GO terms, such as neurotrophin signaling pathway, synaptosome, regulation of protein ubiquitination, and antigen processing and presentation. Further crosstalk analysis revealed these pathways/GO terms were cooperated with each other, and identified several important genes, which might play vital roles to connect these functions. Our network-based analysis of schizophrenia GWASs will facilitate the understanding of genetic mechanisms of schizophrenia.
SCZ Keywordsschizophrenia, schizophrenic
5G3 (Bethesda) 2015 Nov 5: 2453-61
PMID26384369
TitleWhole-Genome Sequencing Suggests Schizophrenia Risk Mechanisms in Humans with 22q11.2 Deletion Syndrome.
AbstractChromosome 22q11.2 microdeletions impart a high but incomplete risk for schizophrenia. Possible mechanisms include genome-wide effects of DGCR8 haploinsufficiency. In a proof-of-principle study to assess the power of this model, we used high-quality, whole-genome sequencing of nine individuals with 22q11.2 deletions and extreme phenotypes (schizophrenia, or no psychotic disorder at age >50 years). The schizophrenia group had a greater burden of rare, damaging variants impacting protein-coding neurofunctional genes, including genes involved in neuron projection (nominal P = 0.02, joint burden of three variant types). Variants in the intact 22q11.2 region were not major contributors. Restricting to genes affected by a DGCR8 mechanism tended to amplify between-group differences. Damaging variants in highly conserved long intergenic noncoding RNA genes also were enriched in the schizophrenia group (nominal P = 0.04). The findings support the 22q11.2 deletion model as a threshold-lowering first hit for schizophrenia risk. If applied to a larger and thus better-powered cohort, this appears to be a promising approach to identify genome-wide rare variants in coding and noncoding sequence that perturb gene networks relevant to idiopathic schizophrenia. Similarly designed studies exploiting genetic models may prove useful to help delineate the genetic architecture of other complex phenotypes.
SCZ Keywordsschizophrenia, schizophrenic