Danon Disease: A Rare Systemic Disorder With the Lamp2-Cardiomyopathy

Danon disease (DD) is a rare and complex pathology, difficult for diagnostics, with multisystemic presentation, which demands for multidisciplinary clinical approach, incl. cardiologists, genetics, neurologists, ophthalmologists and rehabilitologists. The disorder is characterized by a classical triad of signs: phenotype of hypertrophic cardiomyopathy (HCMP), skeletal myopathy and intellect deficit of various grade. The prevalence of DD until recently is not known precisely. It is due to unrecognized origin of myocardial hypertrophy caused by lysosomal glycogen retention in cardiomyocytes. DD is a phenocopy of HCMP, but differs by a malignant course and adverse outcome. Rapid progression of the disease (with the development of heart failure) is known even in moderate myocardial hypertrophy, that requires frequent dynamic follow-up and on-time evaluation of heart transplantation. Is myocardial fibrosis is found in DD, it is prognostically adverse factor for arrhythmia risk and sudden cardiac death. Such patients should be regarded as potential candidates for cardioverter-defibrillator implantation for primary SCD prevention. The article presents with clinical CASe of delayed diagnostics of DD related to mutation in the gene for lisosome-associated membrane protein 2 (LAMP2), in details clinical signs are provided, as differential diagnostics methods.