LAMP2 and Paroxysmal supraventricular tachycardia: Intron 6 is a well-documented mutation hotspot in the LAMP2 gene: IVS6 + 5G > C causes HCM with paroxysmal supraventricular tachycardia, while IVS6 + 1G > T (Case 1) induces similar HCM/WPW but allows partial normal splicing, enabling posttransplant survival.