I am not sure about the term "wild type hERG".
Is it correct if I understand it as "normal hERG" compared with "mutant hERG"?
I agree with your definition.
Wild type hERG does refer to hERG protein without any mutations.
However check if it is wild type hERG1A or hERG1B or a hERG1A/1B heteromer without mutations.
What the heck is hERG?
hERG = "human ether-a-go-go related gene"
Or officially - KCNH2 potassium voltage-gated channel, subfamily H (eag-related), member 2 [ Homo sapiens ]
It is a voltage gated potassium channel. hERG isoforms are expressed throughout the body, but most famous are the hERG1A/1B subunits which are expressed in the cardiac ventricles and contribute to the control of heart beat rhythm through the potassium current IKr
Block of hERG by many different classes of drugs is a major saftey concern for the pharmaceutical industry, because it results in prolonged QT intervals in the cardiac action potential that can lead to ventricular arrythmias and even sudden death due to heart failure. This is known as the acquired Long-QT2 syndrome. Therefore lead compounds are now screened early in development for activity on hERG.
Hereditary Long-QT2 syndrome is is usually caused by mutations in the hERG gene that effect the protein folding and thus the formation of potassium channel tetramers which then traffic to the plasma membrane. The resulting deficit in hERG at the plasma membrane in cardiac myocytes leads to the Long-QT2 syndrome.