Rare PDCD11 variations are not associated with risk of schizophrenia in Japan.

Aim: Rare gene variations are thought to confer substantial risk for schizophrenia. We performed a three-stage study to identify rare variations that have a strong impact on the risk of developing schizophrenia.

Methods: In the first stage, we prioritized rare missense variations using whole-exome sequencing (WES) data from three families, consisting of a proband, an affected sibling, and parents.

New Stethoscope With Extensible Diaphragm.

Background: This study compared the diagnostic efficacy of the common suspended diaphragm stethoscope (SDS) with a new extensible diaphragm stethoscope (EDS) for low-frequency heart sounds.

Methods and results: The EDS was developed by using an ethylene propylene diene monomer diaphragm. The results showed that the EDS enhanced both the volume and quality of low-frequency heart sounds, and improved the ability of examiners to auscultate such heart sounds.

Rare UNC13B variations and risk of schizophrenia: Whole-exome sequencing in a multiplex family and follow-up resequencing and a case-control study.

Rare genomic variations inherited in multiplex schizophrenia families are suggested to play a role in the genetic etiology of the disease. To identify rare variations with large effects on the risk of developing schizophrenia, we performed whole-exome sequencing (WES) in two affected and one unaffected individual of a multiplex family with 10 affected individuals. We also performed follow-up resequencing of the unc-13 homolog B (Caenorhabditis elegans) (UNC13B) gene, a potential risk gene identified by WES, in the multiplex family and undertook a case-control study to investigate association between UNC13B and schizophrenia.

Rare truncating variations and risk of schizophrenia: Whole-exome sequencing in three families with affected siblings and a three-stage follow-up study in a Japanese population.

Rare inherited variations in multiplex families with schizophrenia are suggested to play a role in the genetic etiology of schizophrenia. To further investigate the role of rare inherited variations, we performed whole-exome sequencing (WES) in three families, each with two affected siblings. We also performed a three-stage follow-up case-control study in a Japanese population with a total of 2617 patients and 2396 controls.

Failure to find an association between myosin heavy chain 9, non-muscle (MYH9) and schizophrenia: a three-stage case-control association study.

Several 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.

Two-stage case-control association study of polymorphisms in rheumatoid arthritis susceptibility genes with schizophrenia.

There is strong evidence for a negative association between schizophrenia and rheumatoid arthritis (RA). However, the mechanism for this association is unknown. We hypothesize that these two diseases share susceptibility genes.

Application of the Relapse Risk Scale to alcohol-dependent individuals in Japan: comparison with stimulant abusers.

Objective: To develop and validate the Alcohol Relapse Risk Scale (ARRS) for Japanese alcohol-dependent individuals and to compare the features of relapse risk for alcohol-dependent individuals with those for stimulant abusers.

Methods: The ARRS is a multidimensional self-rating scale consisting of 32 items based on the Stimulant Relapse Risk Scale (SRRS). Two hundred eighteen inpatients and outpatients with a history of alcohol dependence (181 males and 36 females) were recruited, provided informed consent, and were administered the ARRS.

Autosomal linkage analysis of a Japanese single multiplex schizophrenia pedigree reveals two candidate loci on chromosomes 4q and 3q.

We analyzed a large multiplex schizophrenia pedigree collected in mid-eastern Japan using 322 microsatellite markers distributed throughout the whole autosome. Under an autosomal-dominant inheritance model, the highest pairwise LOD score (LOD = 1.69) was found at 4q (D4S2431: theta = 0.

Lack of association between the interleukin-1 gene complex and schizophrenia in a Japanese population.

Interleukin-1 (IL1) is an inflammatory cytokine and exerts neurodegenerative effects in the brain. Several studies have indicated that IL1 is likely to be involved in the pathogenesis of schizophrenia. Recent genetic studies have revealed that the IL1 gene complex (IL,1 alpha, IL1, beta and IL1 receptor antagonist) was associated with schizophrenia, although contradictory findings have also been reported.

No association between the tumor necrosis factor-alpha gene promoter polymorphisms and schizophrenia in a Japanese population.

Tumor necrosis factor-alpha (TNF-alpha) is a pleiotrophic cytokine and exerts neuroprotective and neurodegenerative effects in brain. Several studies have indicated that TNF-alpha is likely related to the pathogenesis of schizophrenia. Recent genetic investigations have revealed that a TNF-alpha gene promoter polymorphism (-G308A) is associated with schizophrenia, although negative findings have also been reported.

No associations exist between five functional polymorphisms in the catechol-O-methyltransferase gene and schizophrenia in a Japanese population.

Catechol-O-methyltransferase (COMT) is one of the enzymes that degrade catecholamine neurotransmitters including dopamine. The COMT gene is located on 22q11.2, a common susceptibility locus for schizophrenia.

Failure to confirm the association between the FEZ1 gene and schizophrenia in a Japanese population.

Fasciculation and elongation of protein zeta-1 (FEZ1) is a binding partner of Disrupted-In-Schizophrenia 1 (DISC1). Because the DISC1 gene is shown to be a causative gene for psychosis in a Scottish family, the FEZ1 gene may well have importance in mental disease. A previous association study that analyzed polymorphisms of the FEZ1 gene in Japanese patients with schizophrenia and control subjects found significant association of the Asp123Glu polymorphism with schizophrenia.

PICK1 is not a susceptibility gene for schizophrenia in a Japanese population: association study in a large case-control population.

The protein interacting with C-kinase 1 (PICK1) has been implicated in the susceptibility to schizophrenia. PICK1 interacts with enzymes and receptors that play roles in the pathogenesis of schizophrenia via glutamatergic dysfunction. Recently, two studies reported associations between schizophrenia and two PICK1 gene polymorphisms, rs3952 in Chinese and Japanese populations and rs2076369 in a Japanese population.

No association between the ERBB3 gene and schizophrenia in a Japanese population.

There is cumulative evidence that neuregulin 1 (NRG1) is a susceptibility gene for schizophrenia. Postmortem studies on brains from schizophrenia patients have revealed changes in the mRNA expression levels of v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (ERBB3), one of the NRG1 receptor genes. These observations suggest that NRG1-ERBB signaling is involved in the pathogenesis of schizophrenia.

RGS4 is not a susceptibility gene for schizophrenia in Japanese: association study in a large case-control population.

The regulator of the G-protein signaling 4 (RGS4) has been implicated in the susceptibility to schizophrenia. RGS4 interacts with ErbB3 that acts as receptors for neuregulin 1 and these proteins may play a role in the pathogenesis of schizophrenia via glutamatergic dysfunction. Recently, two meta-analysis studies provided different interpretations for the genetic association between RGS4 and schizophrenia.

Synergistic association of mitochondrial uncoupling protein (UCP) genes with schizophrenia.

Many studies suggest that mitochondrial dysfunction is involved in the pathophysiology of schizophrenia. We performed a case-control study using tag SNPs in the mitochondrial uncoupling protein genes, UCP2, UCP4, and BMCP1/UCP5, to investigate their association with schizophrenia. These neuronal UCPs are expressed in various brain tissues and may exert a neuroprotective effect against increased oxidative stress.

Association study of a functional promoter polymorphism of the X-box binding protein 1 gene in Japanese patients with schizophrenia.

The functional promoter polymorphism -116C/G of the X-box binding protein 1 (XBP1) gene was found to be associated with schizophrenia in Han Chinese and Japanese subjects, although contradictive negative findings were also reported in European populations. To confirm this association in a Japanese population, the authors conducted a case-control association study. There was no significant difference in both genotype and allele frequencies between the patients and control subjects, suggesting that the XBP1 -116C/G polymorphism might not confer increased susceptibility for schizophrenia in a Japanese population.

No association between the brain-derived neurotrophic factor gene and schizophrenia in a Japanese population.

Brain-derived neurotrophic factor (BDNF) plays important roles in the survival, maintenance and growth of neurons. Several studies have indicated that BDNF is likely to be related to the pathogenesis of schizophrenia. Recent genetic analyses have revealed that BDNF gene polymorphisms are associated with schizophrenia, although contradictory negative findings have also been reported.

Genomewide high-density SNP linkage analysis of 236 Japanese families supports the existence of schizophrenia susceptibility loci on chromosomes 1p, 14q, and 20p.

The Japanese Schizophrenia Sib-Pair Linkage Group (JSSLG) is a multisite collaborative study group that was organized to create a national resource for affected sib pair (ASP) studies of schizophrenia in Japan. We used a high-density single-nucleotide-polymorphism (SNP) genotyping assay, the Illumina BeadArray linkage mapping panel (version 4) comprising 5,861 SNPs, to perform a genomewide linkage analysis of JSSLG samples comprising 236 Japanese families with 268 nonindependent ASPs with schizophrenia. All subjects were Japanese.

Supportive evidence for neuregulin 1 as a susceptibility gene for schizophrenia in a Japanese population.

Schizophrenia is a complex genetic disorder and affects approximately 1% of the population worldwide. Recently, Stefansson et al. identified neuregulin 1 (NRG1) on 8p12 as a susceptibility gene for schizophrenia in the Icelandic population.

Linkage disequilibrium in aquaporin 4 gene and association study with schizophrenia.

Aquaporin 4 (AQP4) has an important role in water homeostasis of human brain and a dysfunction of AQP4 could induce pathological conditions in neuronal activity. Several genome scan studies for schizophrenia found a suggestive linkage on 18q, where human AQP4 (18q11.2-12.

No association of EGF polymorphism with schizophrenia in a Japanese population.

Epidermal growth factor (EGF) signal regulates the development of dopaminergic neurons and monoamine metabolism. It is suggested that EGF protein levels are decreased in the brain and blood of patients with schizophrenia. A recent study has reported that a polymorphism in EGF gene (rs4444903) is associated with schizophrenia in Finnish men.

Genetic and expression analyses of FZD3 in schizophrenia.

Background: Wnt signaling plays important roles in neurodevelopmental processes. Frizzled is a receptor of Wnt protein, and the Frizzled 3 (FZD3) gene was recently reported to be associated with schizophrenia. Our study attempted to confirm associations between FZD3 and schizophrenia in Japanese family and case-control samples.