- Mutations in the genes KCND2 and KCND3 encoding the ion channels Kv4.2 and Kv4.3, conducting the cardiac fast transient outward current (ITO,f), are not a frequent cause of long QT syndrome. Frank-Hansen, R., Larsen, L.A., Andersen, P., Jespersgaard, C., Christiansen, M. Clin. Chim. Acta (2005)









