Introduction. Danon disease is a rare cardiomyopathy (CMP) with multisystem involvement, which is associated with lysosome-associated membrane protein 2 (LAMP2) gene polymorphisms. This protein is the most important regulator of autophagy and is produced mainly in the myocardium, skeletal muscles and brain. This is reflected in the classic disease triad: hypertrophic CMP, skeletal myopathy and cognitive impairment. Danon disease is characterized by maximum penetrance regardless of sex. Expressivity is much less predictable in women, given the X-linked dominant inheritance and mosaicism of cellular production of the LAMP2 protein as a result of random inactivation of one of the X chromosomes.

Brief description. The article presents two clinical cases demonstrating different disease courses in women with Danon disease. The analysis of case records, clinical performance, paraclinical data were carried out.

Discussion. In recent years, the widespread development of molecular genetic diagnostics and imaging methods has led to the accumulation of data on natural course and prognosis of Danon disease. It became clear that in female patients with Danon disease, previously considered mainly as mutation carriers, clinical manifestations can vary from low-symptom phenotypes with isolated CMP to severe multisystemic involvement and early onset. Raising awareness among practitioners about the Danon disease specifics in women, multidisciplinary examination, and genetic testing are the basis for timely diagnosis, risk stratification, and treatment initiation.

Introduction. Analysis and comparison of clinical and functional characteristics of patients with familial hypercholesterolemia (FH) with molecular genetics data make it possible to clarify the disease nature and determine the management strategy taking into account the clinical and genetic status. Considering that biochemical criteria are the leading ones in the diagnosis of FH, the study of family cases complements the disease understanding.

Brief description. An analysis of the genealogical and individual data, physical and general clinical examination of three family members, advanced lipid testing, and vascular ultrasound were performed. A two-stage molecular genetics study was conducted as follows: the first stage involved parallel sequencing of 60 genes associated with FH; the second stage involved DNA assessment by the multiplex ligation-dependent probe amplification method of the low-density lipoprotein receptor (LDLR) gene to identify large deletions.

Discussion. Patients with deletions in LDLR gene exons 2-10 have the most severe clinical and laboratory abnormalities and early development of cardiovascular diseases. Families with FH have the highest concentration of genomic abnormalities that can lead to atherosclerosis lesions even in preschool children and may require non-standard lipid-lowering therapy, including biopharmaceuticals.

Introduction. Duchenne muscular dystrophy is an X-linked muscle disorder caused by the dystrophin absence. This leads to the death of muscle cells and cardiomyocytes and their subsequent replacement with adipose and fibrous tissue. Clinically, this disease manifests itself as progressive muscle weakness and cardiomyopathy. We report a case of a young patient with acute myocardial injury without coronary artery occlusion due to Duchenne muscular dystrophy.

Brief description. A 15-year-old male patient with Duchenne muscular dystrophy, no risk factors for coronary artery disease and known cardiac diseases presented with pressing chest pain. Electrocardiography showed ST segment elevation on the inferior and lateral walls. Given the pressing chest pain, electrocardiographic abnormalities and elevated cardiac biomarkers, an initial working diagnosis of acute myocardial infarction was made and the patient was taken to the catheterization laboratory for coronary angiography, which demonstrated normal cardiac anatomy and coronary arteries without hemodynamically significant stenoses. The patient was discharged from the hospital on day 14 with a final diagnosis of Duchenne muscular dystrophy cardiomyopathy and recommendations for perindopril 5 mg daily and bisoprolol 5 mg daily.

Discussion. Frontline practitioners should be aware of the high prevalence of car diomyopathy in patients with Duchenne muscular dystrophy, which increases with age. Cardiac biomarkers may be chronically elevated in this disease. However, a high suspicion combined with echocardiography and magnetic resonance imaging may help in diagnosing acute myocardial injury in these cases. Based on this case, we discuss the dilemmas of management and follow-up of this complex group of patients.

Introduction. Hypertrophic cardiomyopathy (HCM) with midventricular obstruction (MVO) represents a subgroup of increased risk of adverse outcomes. It contributes to development of apical aneurysm, which is an anatomical substrate for the development of malignant arrhythmias, thromboembolism, as well as progression to end stage systolic heart failure. Genetic causes of HCM with MVO are poorly described in Russian and foreign literature.

Brief description. We present a case of a 54-year-old female patient with a familial HCM with isolated MVO and rare missense variants in the MYH7, FHOD3 and BAG3 genes. The clinical performance was represented by a paroxysmal atrial fibrillation, as well as episodes of nonsustained ventricular tachycardia.

Discussion. According to the European HCM Risk-sudden cardiac death (SCD) calculator, the patient was stratified into an intermediate risk group. However, we also took into account gadolinium-enhanced myocardial areas according to magnetic resonance imaging, as well as no conditions for MVO surgery. This was key in determining the indications for a cardioverter-defibrillator implantation within primary SCD prevention.

Brief description. A 40-year-old male patient with obstructive hypertrophic cardiomyopathy (HCM) developed episodes of fever up to 39,0° C after carotid endarterectomy. Mitral and aortic valve Enterococcus faecium-induced infective endocarditis was diagnosed. Antibacterial therapy was continued for 3 months. As a result, the infectious and inflammatory process was suppressed, but severe mitral and aortic valve insufficiency required surgical treatment.

During the operation, the patient underwent replacement of both affected valves, as well as extended myectomy and cardioverter-defibrillator implantation to prevent sudden cardiac death. Twelve years after surgical treatment of infective endocarditis and HCM, the patient's condition is stable.

Discussion. Patients with HCM have an increased risk of infective endocarditis, but with timely diagnosis and active treatment of endocarditis, a good long-term prognosis is possible. In this case, the combined surgery played an extremely important role.

A previously undescribed electrocardiographic pattern is presented in a female patient with long QT syndrome in the form of combined QRS complex and T wave alternans. Possible electrophysiological mechanisms and prognostic value are discussed