In comparison to wild-type littermates mice lacking Cav3.2 T-type channels do not show any significant differences in heart rate or the ECG waveform morphology; furthermore, no cardiac arrhythmias were observed in Cav3.2 deficient mice indicating that Cav3.2 mediated ICa,T do not contribute significantly to the generation and the conduction of the cardiac impulse (Chen et al., 2003). This evidence concerns the gene CACNA1H and cardiac arrhythmia.