A patient is diagnosed with long QT syndrome and has been commenced on beta-blockers with no symptoms and a QTc of 470 ms. No genetic testing has been performed. She has a 7-year-old daughter and asks about the risks for her child.
What is it appropriate to tell her?
An increasing number of genes have been identified for the long QT syndrome but approximately 80% of patients have a mutation of one of three genes (LQT1–3).
It is always best to perform genetic tests on the subject who has the clearest case of the condition. In this case, this is the patient herself. If a culprit gene can be found, the process of screening family members becomes much simpler.