A male patient aged 20 years old who presented exertional syncope was admitted to the hospital.
At presentation patient was awake and cooperative. Hemodynamic was stable with normal gas exchange and respiratory pattern. No focal neurological signs were found. Physical exam and blood tests were normal.
Electrocardiogram showed normal sinus rhythm, short PR intervals with signs of ventricular preexcitation, left ventricular hypertrophy (LV), like a saddleback ST elevation in leads V1-V2 and several ST-T changes in multiple-lead, T wave inversion.
No extracardiac features were found.
The echocardiography showed features of hypertrophic LV, without LV out flow track obstruction and normal systolic function. There was “ground glass’ appearance of the myocardium and global longitudinal strain reduction and ‘apical sparing’. Analysis of dry blood drops ruled out Fabry disease.
Cardiac magnetic resonance showed marked asymmetric septal hypertrophy with late gadolinium enhancement septal impregnation.
Waiting for the results of genetic tests, the diagnosis of hypertrophic cardiomyopathy (HCM) has been made. Electrophysiological studies were performed and a ventricular tachycardia was induced; accordingly, a subcutaneous defibrillator was implanted.
A heterozygous ALPK3 mutations (del_14bp, rs1466450842) and a heterozygous SCN5A (missense variation (p.Arg 225 Trp)), inherited from the mother and father respectively, were detected in the proband.
The clinical management was very complex because progressive myocardial hypertrophy is one of the main characteristics of cardiomyopathy related to the ALPK3 gene and furthermore, mutations in SCN5A are associated with severe cardiac conduction disorders and degenerative alterations of the conduction system. To the best of our knowledge, this is the first reported case simultaneously reporting both mutations.
Conclusions: diagnosis of cardiomyopathy with hypertrophic phenotype is still a challenge. Precise diagnosis depends on multiparametric approach including molecular genetic techniques.
