Do CASQ2(L167H) and CASQ2(G112+5X) mutations alter intracellular calcium regulation in cardiac myocytes?
CASQ2 mutations L167H and G112+5X associated with CPVT create distinct abnormalities in intracellular calcium regulation that facilitate tachyarrhythmias.
CASQ2(L167H) and CASQ2(G112+5X) alter CASQ2 function in cardiac myocytes, which leads to reduction of active sarcoplasmic reticulum Ca2+ release and calcium content. In addition, CASQ2(G112+5X) displays altered calcium-binding properties and leads to delayed afterdepolarizations. We conclude that the 2 CASQ2 mutations identified in CPVT create distinct abnormalities that lead to abnormal intracellular calcium regulation, thus facilitating the development of tachyarrhythmias.
Barletta et al. (Tue,) studied this question.