Bipolar disorder can be caused by genetic mutations of the calcium channel gene. The calcium channel gene regulates the movement of calcium ions into and out of electrically excitable cells including brain cells (neurons) and heart muscle cells (cardiomyocytes). While calcium channel gene mutations are linked to bipolar disorder, the impact of the same mutation on a bipolar patient’s heart function is unknown.
In a recent publication in Biological Psychiatry OA, researchers determined the impact of this mutation on bipolar patient cardiac function using a new In Vitro Cardiac Diagnostic Tool. Since obtaining a patient’s heart muscle cells for research is not possible, the researchers used innovative patient specific human induced pluripotent stem cells to make heart muscle cells that are created in the lab from the bipolar patient’s own blood cells. The stem cell lines were obtained from the Prechter Program Bipolar Genetics Repository. The researchers did this for a bipolar patient identified to carry a calcium gene mutation and also used innovative CRISPR gene editing to create a cell line where the patient’s mutation was corrected to normal.
The mutation caused slower than normal cardiac electrical impulse propagation and increased risk for development of arrhythmias. This indicates a genotype specific risk for development of cardiac arrhythmias in bipolar patients that can be detected in vitro (outside a living organism). This in vitro bipolar patient specific cardiac diagnostic tool can also be used to screen for the optimal antidepressant medications to avoid unwanted cardiac side effects such as racing heart or palpitations prior to prescription to the patient.