CACNA1C rs1006737 genotype and bipolar disorder: Focus on intermediate phenotypes and cardiovascular comorbidity

Recently, multiple genome-wide association studies have identified a genetic polymorphism (CACNA1C rs1006737) that appears to confer susceptibility for BD. This article aims to summarize the existing literature regarding the impact of rs1006737 on functional and structural neuroimaging intermediate phenotypes. Twenty eight articles, representing 2486 healthy participants, 369 patients with BD and 104 healthy first-degree relatives of patients with BD, are incorporated. Multiple studies have demonstrated structural differences, functional differences associated with emotion-related and frontal-executive tasks, and/or differences in behavioral task performance in risk allele carriers (AA or AG). Results comparing participants with BD to health controls are generally less pronounced than within-group genetic comparisons. The review concludes with an integration of how cardiovascular comorbidity may be a relevant mediator of the observed findings, and proposes future directions toward optimized therapeutic use of calcium channel blockers in BD.