Hypertrophic cardiomyopathy caused by mutations in the <I>PRKAG2</I> gene

Abstract

Clinical observations of three cases of hypertrophic cardiomyopathy caused by mutations in the PRKAG2 gene with a debut in early childhood are presented. The sisters whose father suffered from a severe form of hypertrophic cardiomyopathy in combination with Wolf—Parkinson—White syndrome and died at a young age from progressive heart failure are described. Early manifestation of the disease is characteristic, while there was a combination of ventricular preexitation syndrome and myocardial hypertrophy with rapid progression to extreme values. Hypertrophy was concentric symmetrical and biventricular. The main clinical symptom in the first observation was frequent paroxysms of supraventricular tachycardia. New atrioventricular fenestrations were detected during dynamic observation, insufficient effectiveness of radiofrequency ablation, recurrence of supraventricular tachycardia, and a good response to propafenone were noted. The third clinical case is sporadic, a long-term follow-up for 15 years is presented and clearly reflects the progression of the increase in myocardial hypertrophy and cardiac arrhythmias. The disease debuted from an early age in the form of hypertrophy in combination with severe bradycardia, which made drug therapy difficult. Due to the high risk of sudden cardiac death against the background of extreme myocardial hypertrophy, a cardioverter defibrillator was implanted. Signs of mitochondrial insufficiency according to skeletal muscle biopsy are described.