Cardiac Arrest in a Young Soccer Player With a Pathogenic SCN5A Variant.

backgroundThe SCN5A gene encodes the alpha subunit of the cardiac sodium channel; variants are associated with inherited cardiac diseases including long QT syndrome, sick sinus syndrome, dilated cardiomyopathy, arrhythmogenic cardiomyopathy, and Brugada syndrome. CASE SUMMARY: A 19-year-old male soccer player with a family history of sudden cardiac death collapsed during practice and received an automated external defibrillator shock for polymorphic ventricular tachycardia. Genetic testing identified a pathogenic SCN5A c.4222G>A (p.Gly1408Arg) variant previously associated with Brugada syndrome, although no Brugada pattern was identified on electrocardiogram. A subcutaneous implantable cardioverter-defibrillator was placed. After 8 months without arrhythmias and a reassuring exercise stress test, the patient returned to competitive sports through shared decision-making. DISCUSSION: This case highlights the value of genetic testing after unexplained cardiac arrest and challenges surrounding return-to-sport decisions in inherited arrhythmia syndromes. TAKE-HOME MESSAGES: Consider genetic testing in cases of unexplained sudden cardiac arrest. Accessible automated external defibrillators are essential for safe athletic environments.