Morphological features of the myocardium in LAMP2-cardiomyopathy

Abstract

We present a clinical and morphological case study of a delayed LAMP2-cardiomyopathy (Danon disease) in a 44-year-old woman. LAMP2-cardiomyopathy is caused by impaired autophagy processes due to lysosome-associated membrane protein-2 (LAMP-2) deficiency in cardiomyocytes. This is a rare and diagnostically challenging condition inherited in an X-linked dominant pattern. A medical triad includes myocardial damage with hypertrophic LAMP2-cardiomyopathy, intellectual disability, and skeletal myopa-thy, the first one being the most significant prognostic factor and the main cause of death in these patients. However, autophagy disturbance and lysosomal glycogen accumulation in cardiomyocytes often remain unrecognized as the cause of hypertrophic cardiomyopathy. The report briefly describes disease etiology and epidemiology and outlines the clinical findings of the morphological study focusing on intravital ultra-structural features of structural changes in the myocardium. We provide data from the patient’s history, the results of laboratory and imaging studies, as well as endomyocardial biopsy examination at the light-optical and electron microscopic levels. Keywords: Danon disease, hypertrophic cardiomyopathy, LAMP2, electron microscopy