Early-onset dilated cardiomyopathy associated with a novel CRYAB variant complicated by non-sustained ventricular tachycardia: a case report.

BACKGROUND

Dilated cardiomyopathy (DCM) is a major cause of heart failure in young patients, with a genetic aetiology identified in up to 40% of cases. Variants in *CRYAB*, encoding the small heat shock protein αB-crystallin, are rare but increasingly recognized in inherited cardiomyopathies.

CASE SUMMARY: We report a 16-year-old male who presented with progressive heart failure symptoms and palpitations. Transthoracic echocardiography revealed a dilated left ventricle with severely reduced systolic function. Holter monitoring documented episodes of ventricular tachycardia. Cardiac magnetic resonance demonstrated global biventricular systolic dysfunction and focal mid-wall late gadolinium enhancement in the interventricular septum. Genetic testing identified a novel heterozygous *CRYAB* variant (p.Arg69Cys), confirmed by Sanger sequencing, together with a *PSEN2* variant of uncertain significance. The patient was treated with guideline-directed medical therapy for heart failure and underwent prophylactic implantable cardioverter-defibrillator implantation. Clinical status and left ventricular function improved during follow-up.

DISCUSSION: This case highlights the importance of integrating advanced cardiac imaging and genetic testing in young patients with unexplained DCM and malignant ventricular arrhythmias. Novel *CRYAB* variants may be associated with early-onset DCM and arrhythmic risk, influencing prognostic assessment and management.