It is noteworthy mentioning that the LQTS and torsades de pointes can be acquired and induced by drugs, both cardiac (class I and class III anti-arrhythmics) and non-cardiac drugs (treatments for widely differing conditions).32, , –35 The mechanism of drug-induced arrhythmias seems to involve direct blockade of the hERG K+ channel or inhibition of hERG trafficking.36 Knowing this, an in-vitro IKr/hERG assay using the patch clamp technique has been adopted for early screening of drug candidates in a cardiac safety testing programme. This evidence concerns the gene KCNH2 and cardiac arrhythmia.