Impact of a cis-associated gene expression SNP on chromosome 20q11.22 on bipolar disorder susceptibility, hippocampal structure and cognitive performance.

Background: Bipolar disorder is a highly heritable polygenic disorder. Recent enrichment analyses suggest that there may be true risk variants for bipolar disorder in the expression quantitative trait loci (eQTL) in the brain.

Aims: We sought to assess the impact of eQTL variants on bipolar disorder risk by combining data from both bipolar disorder genome-wide association studies (GWAS) and brain eQTL.

Studies in humans and mice implicate neurocan in the etiology of mania.

Objective: Genome-wide association has been reported between the NCAN gene and bipolar disorder. The aims of this study were to characterize the clinical symptomatology most strongly influenced by NCAN and to explore the behavioral phenotype of Ncan knockout (Ncan(-/-)) mice.

Method: Genotype/phenotype correlations were investigated in patients with bipolar disorder (N=641) and the genetically related disorders major depression (N=597) and schizophrenia (N=480).

DCLK1 variants are associated across schizophrenia and attention deficit/hyperactivity disorder.

Doublecortin and calmodulin like kinase 1 (DCLK1) is implicated in synaptic plasticity and neurodevelopment. Genetic variants in DCLK1 are associated with cognitive traits, specifically verbal memory and general cognition. We investigated the role of DCLK1 variants in three psychiatric disorders that have neuro-cognitive dysfunctions: schizophrenia (SCZ), bipolar affective disorder (BP) and attention deficit/hyperactivity disorder (ADHD).

Molecular genetic overlap in bipolar disorder, schizophrenia, and major depressive disorder.

Objectives: Genome-wide association studies (GWAS) in complex phenotypes, including psychiatric disorders, have yielded many replicated findings, yet individual markers account for only a small fraction of the inherited differences in risk. We tested the performance of polygenic models in discriminating between cases and healthy controls and among cases with distinct psychiatric diagnoses.

Methods: GWAS results in bipolar disorder (BD), major depressive disorder (MDD), schizophrenia (SZ), and Parkinson's disease (PD) were used to assign weights to individual alleles, based on odds ratios.

Genome-wide association study identifies genetic variation in neurocan as a susceptibility factor for bipolar disorder.

We conducted a genome-wide association study (GWAS) and a follow-up study of bipolar disorder (BD), a common neuropsychiatric disorder. In the GWAS, we investigated 499,494 autosomal and 12,484 X-chromosomal SNPs in 682 patients with BD and in 1300 controls. In the first follow-up step, we tested the most significant 48 SNPs in 1729 patients with BD and in 2313 controls.