PLN and hydrops fetalis: MYBPC3 = myosin binding protein C3; MYH7 = myosin heavy chain 7; GT = Genetic testing; HCM = hypertrophic cardiomyopathy; HF = heart failure; SARC+ = sarcomere gene mutations; CPET = cardiopulmonary exercise testing; G+ = genotype-positive; LP/P = likely pathogenic or pathogenic; ECG = electrocardiogram; CMR = cardiac magnetic resonance; TTE = transthoracic echocardiography; DNA = deoxyribonucleic acid; LVH = left ventricular hypertrophy; ICD = implantable cardioverter-defibrillator; SCD = sudden cardiac death; PLN = phospholamban