Background. Non-compaction cardiomyopathy is a group of genetically heterogeneous, poorly studied myocardial diseases with a variety of clinical manifestations (from asymptomatic course to progressive systolic dysfunction with symptoms of chronic heart failure, arrhythmias, and thromboembolic complications). Considering the variety of genetic disorders associated with the development of noncompaction cardiomyopathy, genetic verification of the diagnosis is important for determining the prognosis and conducting genetic counselling of families with cases of the disease.Description of the Clinical Case. The article presents two clinical observations of a severe course of non-compaction cardiomyopathy with remodeling of the heart cavities according to the dilated phenotype. In order to clarify the disease etiology, a molecular genetic study was conducted using the method of direct automatic sequencing with the analysis of targeted regions of 404 genes which mutations are described in hereditary diseases of the heart and blood vessels. After verifying the mutation (in the ACTC1 and MYBPC3 genes), we performed a search for the detected nucleotide substitution in the venous blood samples of parents and in one case — in the fetal DNA sample. The mode of inheritance has been determined; the probability of recurrence of the disease in siblings in subsequent pregnancies has been estimated.Conclusion. The description of clinical cases shows the importance of genetic verification of the diagnosis in patients with non-compaction cardiomyopathy for determining the disease prognosis and developing an algorithm for monitoring relatives of a proband.

The few foreign papers of the last decade have shown the relationship of various pathogenic variants of the ELAC2 gene to heterogeneous phenotypic manifestations, for which the unfavorable prognosis is common, caused by severe cardiomyopathy in the first year of life. The article presents the first clinical observation of a rare variant of the hypertrophic phenotype cardiomyopathy with a fatal outcome in the first year of life, and variants c.887T>C, p.L296P and c.1979A>T, p.K660I of the ELAC2 gene in Russia.The purpose of the work is to present clinical observation of a child with an early manifestation of a hypertrophic phenotype of cardiomyopathy caused by pathogenic variants of the ELAC2 gene.

Aim. To analyze and demonstrate various phenotypes in patients with familial left ventricular noncompaction (LVNC). Materials and methods. In 2013 was created a multicenter registry of LVNC patients. On its basis 30 families with a familial LVNC were selected. Results. 30 LVNC families were selected from the register. From a total of 115 people (probands and relatives) in 71 (61.7%) LVNC was diagnosed (30 probands and 41 relatives with non-compact myocardial criteria). The most common type of remodeling in patients was the dilated type (DT) (n=30), the isolated LVNC with preserved ejection fraction (EF) was slightly less common (n=23), and the hypertrophic type (GT) was detected in 8 patients. 4 patients were diagnosed with the isolated LVNC with a reduced EF. 3 patients were with a combination of non-compact myocardium with congenital heart disease and with a combination of DT and GT (DT+GT). During the analysis of cases a combination of different phenotypes in the same family was observed. The largest number of families was diagnosed with a combination of DT and the isolated LVNC with preserved EF. The development of cardiovascular complications was associated with DT. Conclusion. Family cases of LVNC had different types of myocardial remodeling and variants of clinical course. In one family a combination of different types of left ventricular remodeling is possible. DT is associated with the most severe clinical manifestations. The clinical picture of the isolated LVNC with preserved EF, is the most favorable, but in rare cases, serious clinical manifestations were observed.

Danon disease is a rare hereditary disease with predominant damage to the heart and skeletal muscles. Danon disease is referred to lysosomal storage disorders with severe, progressive course and it often leads to an early mortality. The main cause of Danon disease is the mutations in the LAMP2 gene in the Xq24–q25 chromosome region. Danon disease has X-linked dominant nature of inheritance; women have a milder phenotype with older heart damage. For the first time the disease was described in boys with cardiomyopathy, severe skeletal myopathy and intellectual deficiency. The article presents up-to-date review on Danon disease and case reports of the cardiology department of the National Medical Research Center for Children’s Health, where 5 male patients were observed from 2014 to 2020, and the average age at diagnosis – 13,2 years. During the lab examination three patients demonstrated a significant increase of the heart failure marker (NT-proBNP) – more than 5 thousand pg/ml, the intracellular enzymes was more than 2,5 norms in 4 patients. The Wolff–Parkinson–White phenomenon is recorded in all patients on the ECG. Echocardiography in one patient showed a rare combination of myocardial hypertrophy and non-compact left ventricular myocardium. 2 patients had a combination of hypertrophic and dilated phenotypes with a reduced ejection fraction on Echo and severe myocardial fibrosis on MRI of the heart, which clinically manifested with chronic heart failure refractory to drug therapy, which required heart transplantation.

Dilated cardiomyopathy in children is a very serious disorder with a poor outcome. However, clinical practice has shown that young children have a higher capability to recover cardiac function, which requires an active approach to the prescription of drug therapy. Currently, the combined therapy of chronic heart failure, including ACE inhibitors, beta-blockers, aldosterone antagonists, diuretics, demonstrates high efficiency in reducing the severity of heart failure symptoms, and in improving or stabilizing laboratory and instrumental parameters. Early and adequate administration of drug therapy can improve the prognosis of the disease and prevent an adverse outcome.