Question

4.   John is a 16-year-old who loves to play soccer. His 18-year-old brother, Andre, passed out while playing basketball and has now been diagnosed with long QT syndrome (LQT1). The cardiologist involved suggests that all Andre’s siblings should have a cardiac examination, including an electrocardiogram (ECG), before they play sports. John’s ECG shows a borderline QT prolongation during activity, so the cardiologist recommends genetic testing. John tests positive for the same mutation in the gene KCNQ1 (LQT1) that Andre has, and he is told that he must stop playing soccer. He is counseled to take up a less intense sport, like golf. John is clearly upset and wants to know why this is happening to him. He feels just fine and does not understand why he cannot play his favorite sport.
A.   What is the connection between sports restrictions and Long QT syndrome
B.   How can understanding the genetics help to predict who might be affected by Long QT syndrome if someone in the family is already affected.
C.   How and in what terms will you explain to John why these modifications in exercise are necessary

Answer 1

A. Long QT syndrome is caused due to the long QT interval in the ECG graph which resembles the long repolarisation time in the heart. It is basically the time taken for the heart to come from excited state to normal state i.e. contracted state to relaxed state. This long interval in the contraction is called as Long QT syndrome and due to this if there is a continuous strain on the heart i.e. during excercise or playing, the heart beat will increase but when it slowly decreases there are chances of the person to faint when the heart rhythm comes back to normal. Hence this is the connection between the long QT and playing of soccer.

B. The Long QT syndrome is inherited in a genetic basis and sometimes it is acquried due to other activitites. But the genetically inherited syndrome, there are autosomal dominant inheritance as in the case of Romano–Ward syndrome and also autosomal recessive inheritance as in the case of Jervell and Lange-Nielsen syndrome. Hence the genetic study of the family will be helpful in identifying this trait earlier and giving the appropriate medications and precautions. The genetic inheritance is on chromosome number 11 in Romano ward syndrome and the gene responsible is the KCQN1. In this way genetic testing can be helpful for the early detection of the Long QT syndrome.

C. If the exercise and the soccer playing is reduced there will be reduced stress to the heart and the transititon from a speedy heart to a relaxed beating heart will slowly decrease if the modification is the exercise are taken.

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