GWAS findings for schizophrenia have converged on genome-wide significant evidence for a calcium channel functional complex that has also been implicated in bipolar disorder and autism. These genomic results support increased attention to this pathway, and suggest hypotheses for clinical translation. Multiple approved medications act at calcium channels including some antipsychotics (e.g., pimozide) along with adjuvants for treatment non-response for schizophrenia and bipolar disorder (e.g., the calcium channel blockers verapamil and nifedipine). It is possible that drugs that act on the protein products of CACNA1C and CACNB2 for a different therapeutic indication could be “re-purposed” for the treatment of schizophrenia. For example, there has been at least one clinical trial of the efficacy of isradipine in bipolar disorder (an approved antihypertensive acting at the protein product of CACNA1C, R Perlis, personal communication). In addition, given that many approved antipsychotics increase the cardiac QT interval, genetic variation in calcium channel genes might identify individuals at higher risk of sudden cardiac death. 40,41
