CACNA1C and cardiac arrhythmia: For instance, CACNA1C is an important gene in the transportation of calcium ions and is associated with the increasing risk of arrhythmia, and the A allele of the single nucleotide polymorphism (SNP) rs1006737 in CACNA1C was correlated to a higher risk of bipolar disorder (Ferreira et al., 2008; Napolitano et al., 2012).