The focus of the article is Fabry disease - a rare enough hereditary pathology. The authors present the most up-to-date epidemiological data and features of Fabry disease etiopathogenesis. The offer clinical characteristics of the various types of this disease. The role of enzyme α-galactosidase A and biomarker globotriaosylsphingosine in Fabry disease is describes in detail. The key stages of the biochemical and molecular genetic search in the diagnosis of this pathology are outlined and indicated, the modern possibilities of therapy are described.

The article is devoted to the discussion of approaches to the classification and review of the available literature data on clinical variability and the molecular genetic basis of the pathogenesis of a rare hereditary disease - Ehlers-Danlos syndrome. The presented review will expand the understanding of the pathogenesis and allow to optimize the diagnosis of this syndrome, to determine the tactics of treatment and medical and genetic counseling of burdened families, both to clinical geneticists, specialists in the study of orphan diseases, and to general practitioners, specialists in family medicine and general medical practice.

Depression is a multifactorial mental disorder that is one of the main causes of disability and leads to suicide in 15% of cases. An active search for the genetic component of depression has identified a number of candidate genes that correlate with depression. Recent studies have demonstrated the association of a number of polymorphic variants of the SIRT1 gene with depression. At the same time, the specificity of the distribution of polymorphic variants in the SIRT1 gene among different populations remains unexplored, which may be significant in the analysis of associations. We have studied the structure of the coding part of the SIRT1 gene in the populations of Yakuts, Tuvans, and residents of Novosibirsk. Depending on the ethnic group, there was a change in the frequency of occurrence of polymorphic variants.

Background. This article provides data on the clinical and molecular genetic description of a new hereditary disease with an autosomal recessive inheritance - mucopolysaccharidosis-plus syndrome, first described in the Yakut population and in one Turkish family. The syndrome belongs to the group of lysosomal diseases and was included into the international database of hereditary diseases OMIM under the number # 617303. Aim. To describe clinical and molecular genetic characteristics of mucopolysaccharidosis-plus syndrome in patients observed in Yakutia from 2006 to 2020. Methods. The material for the study was clinical data from genetic records of 17 patients from 15 Yakut families, who were observed and registered in the «Republican genetic register of hereditary and congenital pathology of the Medical Genetic Center of the Republic hospital No. 1 - National Center of Medicine» in Yakutsk city. Results. The clinical phenotype is manifested by typical clinical signs of mucopolysaccharidosis, but with a more severe course of the disease, leading to early infant death of patients. Mucopolysaccharidosis-plus syndrome cannot be diagnosed enzymatically. All patients were found to have a specific p.R498W mutation in the VPS33A gene in a homozygous state, and in their parents in a heterozygous state. Conclusions. A characteristic sign of mucopolysaccharidosis plus syndrome is early manifestation and infant mortality, as well as multisystem damage to organs: lungs, kidneys, heart, central nervous and hemopoietic systems.

Background. Derivative chromosome (der) is a structurally abnormal chromosome, the formation of which can occur as a result of rearrangements with the participation of two or more non-homologous chromosomes, or be the result of aberrations within one chromosome. Differential diagnosis of derivative chromosomes is very important for clarifying the origin of the chromosomal abnormality and for determining the tactics of medical genetic counseling in order to assess the repeated risk of chromosomal imbalance. This work presents seven cases of a derivative chromosome with different origins and mechanisms of formation, as well as a protocol for examining patients with derivative chromosome 8 in the karyotype. Aim: to study the structure and mechanisms of formation of the derivative chromosome 8. Methods. GTG-banded chromosomal analysis, M-FISH, MCB8, FISH with subtelomeric DNA probes, FISH with home-made DNA probes for 8p23.1. Results. As a result of a conventional cytogenetic study of seven unrelated probands a derivative chromosome 8 was found. In all cases, the mechanism of the formation of chromosomal rearrangements was determined. Derivative chromosomes of translocation origin were formed de novo in two cases- der(8)t(8;12) and der(8)t(7;8), and in one case -der(8)t(8;17) - as a result of malsegregation of the paternal reciprocal translocation. In the remaining four cases, the derivative chromosomes were identified as an inverted duplication/deletion 8p due to ectopic recombination. Conclusion. The presented results demonstrate the feasibility of an integrated laboratory approach in the diagnosis of derivative chromosome 8. Characterization of the origin of chromosomal imbalance is an integral part of the examination of patients with structurally abnormal chromosome 8 in the karyotype.

We report on a case of combined chromosomal pathology - partial trisomy on the terminal part of the long arm of chromosome 5 and partial trisomy on chromosome 9 in a newborn with multiple congenital malformations and karyotype 47,XY,t(5;9)(q35;q31),+der(9)t(5;9)(q35;q31)pat. The cause of the chromosomal pathology was a rare abnormality of the formation of gametes in the father’s meiosis II. He is the carrier of the autosomal reciprocal translocation t(5;9)(q35;q31). Healthy carriers of the identical t(5;9)(q35;q31) translocation were identified in three generations of this family. The clinical manifestations of the patient, the possible ways of forming the rearrangement of chromosomes, and the comparison of phenotypes based on the literature data are discussed.