Background: Cardiomyopathies in children are serious, continuously progressing myocardium diseases which are characterized by a variety of the causes, symptoms, implications, and high lethality. More than 400 genes that can cause hereditary heart and vessels diseases are described in scientific literature. The application of a high-performance method of massive parallel sequencing allows to conduct the investigation of genome extended targeted areas revealing the variants and analyzing them (bioinformatics) for pathogenicity.Aims: Identification of a genetic etiology of hereditary cardiomyopathies development in children’s population of the Russian Federation.Materials and methods: The research included 103 patients with various phenotypes of cardiomyopathies aged from 3 months up to 17 years 9 months who at the moment of examination were observed in the cardiology department and the department of recovery treatment with cardiovascular diseases in the NMRCCH. All patients were performed massive parallel sequencing analyzing the targeted areas of 404 genes which mutations lead to the development of heart and vessels hereditary diseases.Results: The diagnostic algorithm based on the method of a massive parallel sequencing was developed. 176 258 minor options were identified in the explored target areas of genome of 103 patients. An average number of the revealed nucleotide replacements different from the reference sequence was 1711. We observed that about 40% of all variants founded by our means were found in MYH7, MYBPC3, TTN, MYH6, SCN5A, DSC2 and TPM1 genes. Bioinformatics analysis allowed revealing 68 novel genome variants associated with cardiomyopathy development. The reliable association of carriage of pathogenic option in MYBPC3 gene with development of hypertrophic cardiomyopathy in the Russian children was found.Conclusions: The application of the offered algorithm allowed establishing laboratory diagnoses to 99 (96.1%) patients out from 103 investigated subjects including the syndromal and non-syndromal forms of heart and vessels hereditary diseases which showed a cardiomyopathy phenotype.

Noonan-like syndrome with loose anagen hair is a rare inherited disease caused by heterozygous mutation in theSHOC2gene. The disease was first described in 1991. The main clinical manifestations of the disease are phenotype features similar to those observed in Noonan syndrome: orbital hypertelorism, eyelid ptosis, low-set, and posteriorly rotated auricles, as well as skin and hair lesions, development delay, loose anagen hair, cardiovascular disorders, and mental retardation. It has an autosomal dominant mode of inheritance. We have described three clinical cases of this disease for the first time in Russia. All children in this group had a Noonan-like phenotype, macrocephaly, wide, short neck, hair and skin lesions, congenital heart disease, development delay of different severity, and hypotonia. One child had hypertrophic cardiomyopathy, nonobstructive form, aneurysmal dilatation of interatrial septum, minor dilation of the pulmonary artery and atria, apical aneurysm other cases showed a congenital defect of the urinary system. These patients have thin, sparse, slowly growing hair, dark skin. One girl was diagnosed with multiple capillary haemangiomas on her head and trunk. Pathogenic nucleotide variant c.4AG, p.S2G in heterozygous state of the SHOC2 gene was revealed in all our patients. The same was described previously in patients with this syndrome. Differential diagnosis at suspicion on Noonan-like syndrome with loose anagen hair should be carried out with Noonan syndrome, Cardiofaciocutaneous syndrome (CFC), Costello syndrome.