Genetic and functional analyses implicate microRNA 499A in bipolar disorder development.

Bipolar disorder (BD) is a complex mood disorder with a strong genetic component. Recent studies suggest that microRNAs contribute to psychiatric disorder development. In BD, specific candidate microRNAs have been implicated, in particular miR-137, miR-499a, miR-708, miR-1908 and miR-2113.

Whole-exome sequencing of 81 individuals from 27 multiply affected bipolar disorder families.

Bipolar disorder (BD) is a highly heritable neuropsychiatric disease characterized by recurrent episodes of depression and mania. Research suggests that the cumulative impact of common alleles explains 25-38% of phenotypic variance, and that rare variants may contribute to BD susceptibility. To identify rare, high-penetrance susceptibility variants for BD, whole-exome sequencing (WES) was performed in three affected individuals from each of 27 multiply affected families from Spain and Germany.

Identification of rare variants in KCTD13 at the schizophrenia risk locus 16p11.2.

Duplications in 16p11.2 are a risk factor for schizophrenia (SCZ). Using genetically modified zebrafish, Golzio and colleagues identified KCTD13 within 16p11.

DNA sequence variants in the metabotropic glutamate receptor 3 and risk to schizophrenia: an association study.

Objectives: Recent studies investigating the association of DNA variants in the metabotropic glutamate receptor gene (GRM3) with schizophrenia susceptibility revealed conflicting results. In this study, we focused on DNA sequence variants, for which association was reported and attempted to replicate association with schizophrenia or with cognitive deficits known to be present in patients with schizophrenia.

Methods: A sample of 242 families with affected offspring and five single nucleotide markers located in the genomic region of GRM3 has been used to replicate association with schizophrenia.

Further evidence for association of variants in the AKT1 gene with schizophrenia in a sample of European sib-pair families.

Background: Involvement of AKT signaling pathways in schizophrenia has been recently suggested, on the basis of several lines of evidence. In addition to impairment of protein-levels and phosphorylation levels in the pathway, association of DNA sequence variants in the AKT1 gene with schizophrenia has been detected in a family sample.

Methods: We investigated the reported association of DNA sequence variants in the AKT1 gene in a sample of 79 sib-pair families with schizophrenia using the five single nucleotide polymorphisms (SNPs) of the original study and two additional SNPs in the neighborhood of the SNP for which association had been reported.

Serotonin transporter promoter and intron 2 polymorphisms: relationship between allelic variants and gene expression.

Background: Two polymorphic regions of serotonin transporter (5-HTT) gene: a 44 base pair (bp) insertion/deletion in the promoter region (5-HTTLPR) and a 17 bp variable number of tandem repeats in second intron (VNTR-2), seem to modulate the gene's transcription in allele-dependent manner.

Methods: We have earlier demonstrated association with 5-HTT gene in families multiply affected by schizophrenia. Here, we investigated separate and combined effects of VNTR-2 and 5-HTTLPR on the rate of peripheral 5-HTT transcription in a sample of offspring from those families.

Association of tumor necrosis factor alpha gene -G308A polymorphism with schizophrenia.

Background: Tumor necrosis factor alpha (TNFalpha), a cytokine involved in inflammatory processes, has been implicated in the pathophysiology of schizophrenia. The chromosomal location in the major histocompatibility complex (MHC) region on 6p21.1-21.

[No association of 141C-ins/del polymorphism in the D2 dopamine receptor gene in schizophrenia].

Recently, a putative functional polymorphism (-141C Ins/Del) in the 5'-flanking region of the dopamine D2 receptor was found. An association of the Ins allele with schizophrenia has been described in a Japanese sample. In the present study this association was examined in a German schizophrenia patient population.

[No Association of the - 141C Ins/Del Polymorphism of the Dopamine D2 Receptor with Schizophrenia].

Recently, a putative functional polymorphism (- 141C Ins/Del) in the 5'-flanking region of the dopamine D (2) receptor was found. An association of the Ins allele with schizophrenia has been described in a Japanese sample. In the present study this association was examined in a German schizophrenia patient population.

Support for association of schizophrenia with genetic variation in the 6p22.3 gene, dysbindin, in sib-pair families with linkage and in an additional sample of triad families.

Genetic variants in a gene on 6p22.3, dysbindin, have been shown recently to be associated with schizophrenia (Straub et al. 2002a).

Investigation of linkage and association/linkage disequilibrium of HLA A-, DQA1-, DQB1-, and DRB1-alleles in 69 sib-pair- and 89 trio-families with schizophrenia.

The hypothesis that HLA antigens confer susceptibility to schizophrenic disorders has been tested by studying linkage and association in a family sample with 69 sib-pair families. Suggestive evidence for linkage was obtained by nonparametric multipoint LOD score analysis with a maximum around DQB CAR (P = 0.0004), a microsatellite marker that is in linkage disequilibrium with the HLA antigen DQB1.