Firstly, perhaps our most interesting discovery was related to the fact that we detected the Val336Leu PRKAG2 variant in the patient in whom Fidzianska et al. [11] described ultrastructural changes and the presence of autophagal vacuoles in cardiomyocytes in a heart muscle biopsy taken during the transition period from HCM to HF. Here, PRKAG2 is linked to hydrops fetalis.