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Introduction. Borrelia miyamotoi is a pathogen causing erythema-free ixodid tick-borne borreliosis (ITBB), a disease widespread in Russia. The genome of B. miyamotoi contains genes of multiple variable major proteins (Vmps). Vmps fall into two families — Vsps and Vlps (with subfamilies δ, γ, α and β). At a particular time, a single B. miyamotoi expresses only one variant of Vmp gene. The purpose of the work is to develop a technique for identification of the Vmp present at the expression site. Materials and methods. The technique is designed in the format of a real-time multiplex PCR. It was tested by using B. miyamotoi DNA samples extracted from blood collected from 172 ITBB patients and 109 ticks. The samples were collected in 14 regions of Russia. Results. The new technique made it possible to identify the expressed Vmp in 82% of the examined samples, thus having demonstrated its efficiency. Negative results were much less often observed with samples from patients than with samples from ticks. At the same time, the percentage of samples with one type of Vmp is identical for clinical samples and ticks, while the percentage of samples containing concurrently two types of Vmps is significantly higher among samples from patients with the most frequent occurrence of the Vlp-δ and Vsp combination. Discussion. The frequent occurrence of the combination of two Vmp types in the blood samples can indicate the concurrent presence of several subpopulations of B. miyamotoi in ITBB patients. A new antigenic Vmp variant is synthesized after protective antibodies have been produced for the major protein of the strain transmitted by a tick. This phenomenon known as immune evasion allows the pathogen to persist within a host. Conclusion. The developed technique of real-time multiplex PCR allows to simultaneous detect of several antigenic variants of the variable basic surface proteins of B. miyamotoi. The study of the antigenic spectrum of B. miyamotoi strains in comparison with the characteristics of conserved regions of the genome by the method of multilocus sequencing will clarify the stages of evolution and distribution of B. miyamotoi sensu lato.

Background. In accordance with the World health organization clinical guidelines, the analysis of somatic mutations in the CALR gene, as well as mutations in the JAK2 and MPL genes, are included in the list of criteria for the Ph-myeloproliferative neoplasms diagnosis.More than 50 different mutation variants have been found in the CALR gene, among which the most frequent are a 52 bp deletion (c.1092_1143del), also called type 1, and a 5 bp insertion (c.1154_1155insTTGTC), also called type 2 (88 %).The remaining 12 % are other type less frequent indels or combinations thereof.It is most convenient to use sequencing methods to identify all possible variants of CALR mutations. It is also important to develop inexpensive screening test that can detect any mutations in the analyzed DNA fragment of CALR gene. This method can be heteroduplex analysis followed by electrophoresis on polyacrylamide gel (PAGE).The objective: to develop and demonstrate the feasibility of using heteroduplex analysis with separation of the PCR product by electrophoresis on non-denaturing PAGE for the CALR exon 9 mutations detection as the screening test. Materials and methods. DNA samples of 13 CALR-positive patients with different phenotypic variants of Ph-myeloproliferative neoplasms were screened by heteroduplex analysis. For the most common variants of CALR mutations (c.1092_1143del and c.1154_1155insTTGTC), a threshold determination of the mutant allele presence was analyzed.Nucleotide sequence of exon 9 fragment was determined using Sanger sequencing. Also, all 13 samples were analyzed using the pyrosequencing method to assess the allelic burden level.Results. Heteroduplex analysis revealed mutations in exon 9 of the CALR gene in all 13 patients. The threshold determinations of the method in the case of the c.1154_1155insTTGTC and c.1092_1143del analysis are 6.25 % and 3.13 % of the mutant allele presence in the patient sample, respectively.Conclusion. The proposed variant of the heteroduplex analysis with separation of the PCR product by electrophoresis on non-denaturing PAGE can be recommended for use as the preliminary screening test which is carried out before the confirming sequencing methods for the different indels (or combinations thereof) CALR mutations determine.The presence of heteroduplexes indicates the presence of a mutation, even if the mutant product is not visualized (in case of small mutations).

Antipsychotic drugs are a critical modality in managing of schizophrenia. Although medications can be highly effective, response varies and some patients derive considerably less benefit than others. Long-term use of antipsychotic drugs is associated with the development of adverse reactions. Te safety advantages of the atypical drugs havebeen questioned because of their propensity to induce weight gain and alter glucose and lipid metabolism. Antipsychotic-induced weight gain is a common cause of self-discontinuation of treatment and a significant deterioration in the quality of life in patients with schizophrenia. Te severity of adverse reactions when taking antipsychotics in different patients varies, which be associated with genetic factors. Antipsychotic induced weight gain is a major health concern and unfortunately, there is no predictive tool to identify who are high risk individuals. Te LEP, LEPR and NRY genes represents a compellings candidates for genetic studies of antipsychotic-induced weight gain. Candidate gene selection should rely on current knowledge on the molecular pathways to weight gain, antipsychotic pharmacokinetics and pharmacodynamics, as well as possible disease-related genetic links to the side effects under study. Pharmacogenetics will provide rational treatment based on matching antipsychotics to a patient’s DNA profile, thus, potentially providing effective treatment with minimal side effects to outliers and mean responders to a given antipsychotic medication.

Relevance. Population migration can play a crucial role in the spread of invasive strains of meningococcus, initiating outbreaks of meningococcal infection, and changing the incidence at the local level.Aim. To assess the prevalence of meningococcal carriage among migrants arriving in Moscow and to characterize the antigenic and genetic properties of carrier strains of meningococcus.Materials and methods. The study was conducted in March 2020 at the bases of the Multifunctional Migration Center of Moscow and the Federal Budget Institution of Science «Central Research Institute of Epidemiology». Samples of nasopharyngeal mucus were collected from 352 people. Nasopharyngeal strains of meningococcus were identified and identified using microbiological, serological, and molecular biological methods.Results. The overall level of the carriage was 5.7%. Of the twenty selected strains, 10 have a serogroup defined: Y – 5 strains, W - 3, A, and B – 1 each. The obtained genetic and antigenic characteristics do not allow talking about the import into the RF of representatives of known hypervirulent clonal complexes. In this study, strains were identified that are part of the clonal complex ST-175 complex, which has not been previously described in the Russian Federation.Conclusion. It seems promising to continue the dynamic monitoring of carriage of meningococcus in various groups, including among people entering the country to obtain a migration patent, as well as identifying risk factors for acquiring carriage. The data obtained will supplement current information on the incidence of the generalized form of meningococcal infection and will be crucial for determining the epidemiology at the country level, the population groups responsible for the transmission of the disease, and the need for targeted vaccination.

Background. There are problems related to both quantitative assessment of an allele burden level of a mutant gene and interpretation of results in DNA samples with the burden level of the mutant allele less than 15–20 %, when using Sanger sequencing for analyzing somatic mutations. Applied Biosystems (USA) has developed new software Minor Variant Finder, which allows determining mutations with the allele burden level from 5 %.The objective: to determine the allele burden level and identification of minor variants of somatic mutations in the ASXL1, JAK2 genes and BCR-ABL oncogene using Minor Variant Finder software in patients with myeloproliferative neoplasms.Materials and methods. The level of mutant allele burden for 15 patients with myeloproliferative neoplasms was determined by the identified mutations using the Minor Variant Finder software, after analysis of point somatic mutations in the ASXL1, JAK2 genes and BCR-ABL oncogene by Sanger sequencing.Results. The allele burden level in all 5 ASXL1-positive samples and BCR-ABL-positive sample was determined as higher than 20 % using the Minor Variant Finder software. The allele burden level in 2 cases was higher than 20 % and in 7 cases lower than 20 %, when we analyzed 9 JAK2-positive samples.Conclusion. Minor Variant Finder software can be used to estimate the allele burden level and to identify minor variants of somatic mutations in the ASXL, JAK2 and BCR-ABL genes.

Hemorrhagic fever with renal syndrome (HFRS) is a zoonotic infection disease caused by Orthohantavirus which belongs to Hantaviridae family. This article is a brief review of recent data about genetic factors which play a role in individual predisposition toward HFRS. There are reports discovered associations of polymorphic sites with HFRS severity and risk complications. Polymorphic sites in genes which code proteins of immune (МНС, TNF, IL1) and endothelial (VE-cadherin) systems, blood coagulation (SERPINE1, ITGA2B, NOS) and detoxification (CYP1A1, GSTP1) systems and their links with disease are described in this article. HLA haplotypes B*08-DRB1*03 and B*46-DRB1*09, B*51-DRB1*09 are associated with severe forms of HFRS-PUUV and HFRS-HTNV respectively. TNF A-allele and AA-genotype in -308G>A SNP (rs1800629), CDH5 ТТ-genotype in 1550T>C SNP, SERPINE1 G-allele in -844A>G SNP (rs2227631), alleles HPA3 b, NOS2A*11 and NOS2A*11/NOS2A*12-genotype, CYP1A1 1А2С-genotype in SNP (rs1048943) and GSTP AG-genotype in SNP (rs1695) demonstrated associations with severe HFRS. Differences in the expression levels of GATA3, T-BET, CD3, IFNβ, NFkB, STAT1 and MxA genes in cell cultures stimulated by hantavirus. Expression of GATA3 was significantly higher in cell cultures of patients with severe HFRS than with a mild form. In contrast, MxA gene expression was up-regulated in cell cultures of patients with mild HFRS-PUUV. Considering individual genetic factors of HFRS patients would allow defining the best tactic of therapy and prophylaxis in this way. And as a result of applying this treatment in the clinical practice decrease of unfavorable disease outcome would occur.

Schizophrenia is a socially significant mental disorder characterized by early onset and high time and financial expenditure on treatment. The basic drugs in these patients are antipsychotics that are highly effective against the positive and negative symptoms of schizophrenia, but at the same time have a wide range of adverse reactions (ARs). The clinical effect and tolerability of antipsychotics are variable and depend on the characteristics of genetically determined mechanisms (transportation, biotransformation, and elimination).The paper describes a clinical case of a female patient with schizophrenia who has been noted to be unresponsive to antipsychotic therapy for some years after the onset of the disease. After pharmacogenetic testing, she was found to be homozygous for the nonfunctional allelic variant CYP2D6*4 (1934 G>A, rs3892097), which was the reason for the complete shutdown of isoenzyme 2D6 activity and the development of ARs in the use of initial doses of antipsychotic drugs, as well as for an increase in the severity of ARs with aggravation of psycho-producing symptoms with an even slow titration of the daily dose.

Somatic mutations associated with oncological diseases, including Ph-myeloproliferative neoplasms (Ph-MPN), are very diverse, occur with different frequencies and different allelic burden levels. Therefore, at the initial stage of performing molecular-genetic diagnostic procedures, it is desirable to be able to conduct screening tests in the laboratory. This is especially important when analyzing rare and diverse mutations. Analysis of high resolution melting curves (HRM analysis), which has high sensitivity and is suitable for screening all types of mutations, in a number of studies is proposed for the analysis of Ph-MPN associated mutations in the JAK2 and CALR genes. For analysis of somatic mutations in the majority of literature sources that we reviewed, the authors use the LightCycler (Roche) thermocycler and much rarely the CFX96 (Bio-Rad), which is often presented in Russian scientific and practical and medical organizations. The aim of the study was to screen the somatic JAK2 and CALR mutations by HRM analysis using the CFX96 thermocycler and the Precision Melt Analysis software (Bio-Rad, USA) for patients with Ph-MPN. In the present research, HRM analysis was conducted on the DNA samples from patients with mutations in the JAK2 or in the CALR gene. The Precision Melt Analysis software identified all variants of the analyzed mutations, both a single nucleotide substitution in the JAK2 gene (with allelic burden level in the range of 5-40%), and various indel mutations in the CALR gene (with allelic burden level in the range of 40-50%) Therefore, the HRM analysis that was conducted on the CFX96 allows screening of highly specific mutation for the diagnosis of Ph-MPN in the exon 14 of the JAK2 gene and in the exon 9 of the CALR gene. The inclusion of this screening research in the laboratory testing algorithm improves the efficiency and accessibility of molecular genetic technologies in the diagnosis of Ph-MPN.

Intensive development of DNA analysis technologies and large-scale genome-wide association studies have led to accumulation of a large array of data on the relationship between genetic factors and various phenotypic manifestations, including monogenic and polygenic hereditary diseases. This has greatly extended the capabilities of clinical diagnostics and predictive medicine in the field of socially significant diseases. For example, the role of a genetic component of the risk for such multifactorial and polyetiologic disease as stroke is now actively explored. Large-scale studies have revealed both general and specific genetic markers associated only with a certain type and subtype of stroke. This review analyzes the current state of the problem of using genetic markers for diagnosis of predisposition to stroke, complex issues associated with multiplicity of risk factors for stroke, and potential development in this area.

Introduction. The invasive meningococcal disease (meningitis and/or septicemia) is actual problem of public health in Russia. Neisseria meningitidis isolates are classified into serogroups, PorA/FetA VRs, sequence types and clonal complexes. The growth of the invasive forms of meningococcal infection caused by isolates with «W: P1.5,2: F1-1: ST-11 (cc11)» profile requires attention for extended genotyping because the discriminating ability of classical MLST and antigens typing does not allow to answer the question about genetic and antigenic features of the pathogens and their epidemic potential. Materials and Methods. Four N. meningitidis serogroup W isolates associated with invasive meningococcal disease in Moscow (Russia) were characterized by next-generation sequencing. Three isolates were sequenced directly from cerebrospinal fluid samples and one -as a bacterial culture. All isolates were characterized earlier and the data were published in the PubMLST data base (id38565, id38573, id50225 and id50241). Genomic DNA was sequenced on Illumina MiSeq instrument. Results and Discussion. Obtained sequences allowed us to characterize four meningococci isolates for more than 1400 loci from the core genome MLST scheme. We have analyzed the core genome MLST scheme information about surface-antigen coding sequences. Housekeeping genes sequences were used to determine eMLST profile, ribosomal protein genes and some antibiotic resistance associated genes. We have characterized some ribosomal protein genes and antibiotic resistance associated genes. Based on eMLST profiles we noticed that there are at list two clones of N. meningitidis serogroup W inside complex ST-11/ET-37 clonal complex circulating in Moscow during 2016. An eMLST profile of isolates id50225 and id50241 differs in 3 loci out of 20. Application of the approach based on next-generation sequencing in routine epidemiological surveillance dramatically increases the amount of data and genotyping discriminating ability.

With the aim to determine specific genetic characteristics of the population of Moscow region, we determined allele frequencies of 48 polymorphic loci (SNP) associated with the increased risk of ischemic stroke development. The genotype frequency distribution for all the SNPs corresponds to Hardy–Weinberg equilibrium. Comparison of the allele frequencies with those obtained for Caucasian populations from the databases dbSNP and 1000 Genomes Project revealed significant differences for two SNPs (rs556621 and rs556512) and seven SNPs (rs556621, rs556512, rs1801133, rs1799983, rs5918, rs328, and rs2398162), respectively. The revealed genetic features of the population make it possible to increase the accuracy and reliability of the individual genetic risk assessment of development for multifactorial diseases in the examined population.

Aim: The purpose of our study was to analyze the predictive ability of the multiplicative model of genetic risk of nonlacunar ischemic stroke (IS) for independent samples from Russia. Patients & methods: A total of 181 patients and 360 healthy controls were included in this study. The discriminative accuracy of model was evaluated by the area under the receiver operating characteristic curve (AUC). Results: Classification model based on 15 single-nucleotide polymorphisms (SNPs), which are associated with a cardioembolic subtype of IS, had an AUC of 0.62 in patients with corresponding subtypes and an AUC of 0.58 for all patients. Conclusion: Risk calculation approach based on IS-associated SNPs had satisfactory performance in predicting the predisposition to the disease.

To develop a method of the complex assessment of genetic risk for ischemic stroke (IS) and evaluate its effectiveness.Genotyping of 182 patients with atherothrombotic and cardioembolic subtypes of IS and 360 healthy individuals of 48 single nucleotide polymorphic loci (SNP) associated with the risk of II and its subtypes was performed.In each group of SNPs, composite indicators of genetic risk of IS in groups of patients and healthy controls were identified. Differences between the calculated values of the genetic risk in these groups were significant (p0,05). The quality of the binary classification validated by ROC-analysis confirmed the predictive potential of the proposed method of risk calculation for determining the genetic predisposition to the development of IS.Цель исследования. Разработка методики комплексной оценки генетически обусловленного риска развития ишемического инсульта (ИИ) и оценка ее эффективности. Материал и методы. Проведено генотипирование 182 больных с атеротромботическим и кардиоэмболическим подтипами ИИ (группа больнах) и 360 здоровых (контрольная группа) по 48 однонуклеотидным полиморфным локусам (SNP), ассоциированным с риском развития ИИ и его подтипов. Результаты и заключение. Для каждой группы SNP в соответствии с предложенной моделью определены комплексные показатели генетического риска развития ИИ в группе больных и контрольной группе. Различия между группой больных и контрольной группой по показателям генетического риска определены как статистически значимые (p0,05). Качество бинарной классификации, проверенное ROC-анализом, подтверждает прогностический потенциал использования предложенной модели расчета риска для определения генетической предрасположенности к развитию ИИ.