Newborn screening is important for the early detection of many metabolic disorders, aimed at the earliest possible diagnosis and treatment of affected newborns, to prevent the morbidity, mortality, and disabilities associated with an inherited metabolic disorder. Screening program includes several important parts testing, education, follow up, diagnosis, treatment, management, and evaluation. In recent times, advances in laboratory technology such as tandem mass spectrometry (MS/MS), which is more specific, sensitive, reliable, and comprehensive than traditional assays, has increased the number of genetic conditions that can be diagnosed through neonatal screening programs at birth. Today different countries have different list of diseases included in screening programs. This is due to the specifics of the health system of countries, the available financial resources, the activity of the professional community and the social orientation of society as a whole. The main task in the adoption of screening programs is to keep a balance between quantitative (number of screened diseases) and quality (screening efficiency) indicators. In recent years, with the help of tandem mass spectrometry, technologies for detection of lysosomal storage diseases have been actively developed. Pilot projects of different countries have shown the effectiveness of this method. They have made it possible to clarify the frequency of diseases and the range of mutations. So the possibility of incorporating LSD tests into mass screening is widely discussed today. The NGS method, which allows relatively quick search for mutations in a large number of genes, has also proved to be an effective way of diagnosing inherited metabolic diseases. The prospect of implementing NGS in NBS programs is actively discussed. This method has some problems, such as clinical analysis, interpretation of results, storage of sequencing data.

According to neonatal screening in the Republic of Kazakhstan for the period since 2007 year to 1 half of 2017 year 2520053 newborns were screened. The middle coverage of neonatal screening in the Republic of Kazakhstan since 2011 year was 73.1%, the middle coverage varies in different regions of the Republic of Kazakhstan. Since 2007year 105 children with phenylketonuria and 336 with congenital hypothyroidism have been identified in the neonatal screening program. The regional features of the frequency of PKU and CH are noted, which can be determined by population characteristics, in particular by ethnic composition, and by the variation in coverage by neonatal screening of regions.

Application of new diagnostic technologies for early detection of hereditary metabolic diseases revealed their significant advantages (high analytical specificity and sensitivity, high bandwidth) and the appropriateness of their use in neonatal screening. Decrease of the number of false positive results, one definition of a large number of biochemical markers in a minimum quantity of biological sample made it possible to reduce the total duration of laboratory research and to ensure high performance diagnostic process. However, the lack of specificity of the markers requires to use molecular-genetic research as a supporting method of diagnosis. Speed of execution, the relative low cost, relatively simple interpretation of the obtained results of high-performance next-generation sequencing (NGS) allowed to recommend it as a the final stage of diagnosis of neonatal screening.

The article reviews the analysis of work of medical and genetic service in Buryatia on mass newborn screening. Over a period from 2005 to 2016 there was carried out the comparison of hereditary enzimopatiya frequencies (fenilketonuriya, congenital hypothyroidism, adrenogenital syndrome, cystous fibrosis, galactosemia) revealed as a result of mass neonatal screening in the Republic of Buryatia with data on other Russian regions. The received frequencies of the hereditary metabolic diseases tested on neonatal screening for Buryatia keep within the range of the sizes described for various regions of the country. This information can be taken as a basis for preventive programs of the medical and genetic help to the population of the Republic of Buryatia Prospects for the development of preclinical diagnosis of metabolic diseases is an increase in the range of screened diseases using tandem mass spectrometry.

MtDNA polymorphism was studied in the group of patients with advanced carotid atherosclerosis and in controls with subclinical atherosclerosis. Frequencies of main European mtDNA haplogroups were determined. Comparison of the haplogroups frequencies has revealed higher frequency of haplogroup J in controls (17.65%) than in patients (4.55%; p = 0.0145). The results suggest protective effect of haplogroup J in relation to advanced carotid atherosclerosis.

Objective. To develop a DNA technology for the prognosis of the effectiveness of neoadjuvant chemotherapy of breast cancer (BC) based on the determination of the methylation state of a limited set of DNA methylation markers by the method of multilocus methylation sensitive restriction enzyme polymerase chain reaction (MSRE-PCR). Material and methods. The research workflow was as follows. (1) Carry out a genome wide DNA methylation analysis on biopsy samples of breast tumors prior to anthracycline neoadjuvant chemotherapy. (2) Develop a limited panel of DNA methylation markers, the most informative for the prognosis of the effectiveness of neoadjuvant chemotherapy. (3) Develop and optimize the laboratory protocol of multi-locus MSRE-PCR for determining the methylation status of the markers in the panel. (4) Evaluate the diagnostic properties of the resulting panel of DNA methylation markers. Genome wide DNA methylation analysis of 27 BC biopsy specimens of the luminal B subtype, taken before the treatment under ultrasound guidance, was performed using the XmaI-RRBS method. According to the results of XmaI-RRBS, 10 genes have been selected, the state of methylation of the promoters of which most effectively marks epigenetic subtypes of tumors with different responses to neoadjuvant chemotherapy. Methylation status of the selected markers was next determined by MSRE-PCR with three primer pools in a sample of 40 BC biopsy specimens of the luminal B subtype taken before the treatment. Evaluation of the diagnostic properties of the system was carried out by ROC analysis. Results. By the genome wide DNA methylation analysis, the SLC9A3 , C1QL2 , DPYS , IRF4 , ADCY8 , KCNQ2 , TERT , SYNDIG1 , SKOR2 and GRIK1 gene regions were identified as the most informative markers of BC sensitivity to anthracycline neoadjuvant chemotherapy. To conduct locus-specific testing of the methylation status of these markers we have developed a multi-locus MSRE-PCR system. Based on the results of the locus-specific testing, the diagnostic properties of the system were determined: the area under the ROC curve was 84%, the sensitivity of the system was 82% with the specificity of 80%, the accuracy was 82%. Conclusion. The system including a limited number of DNA methylation markers, makes it possible to effectively predict the response of a luminal B subtype breast tumors to anthracycline neoadjuvant chemotherapy by an analysis of biopsy material obtained prior to treatment.

Matrix metalloproteinases and their inhibitors contribute to the regulation of cell-cell interactions and maintain tissue structure and function. We have analyzed DNA methylation at the promoter regions of 11 matrix metalloproteinases genes ( MMP2, MMP11, MMP14, MMP15, MMP16, MMP17, MMP21, MMP23B, MMP24, MMP25, MMP28 ), and 4 inhibitors of matrix metalloproteinases genes ( TIMP1, TIMP2, TIMP3, TIMP4 ). Collectively members of these families take part in regulation of matrix proteins degradation, signal transduction, adhesion, migration, cell differentiation, apoptosis and angiogenesis. Abnormal methylation frequencies at the promoter regions of genes MMP2, MMP23B, MMP24, MMP25, MMP28 in breast cancer accounted for 7,7%, 17%, 11,9%, 15,4% and 4,9% respectively. Promoter regions of genes TIMP1, TIMP4, MMP14 MMP21 were constitutively methylated in breast tissue.

We performed a comprehensive molecular genetic examination of patients with retinoblastoma. For establish molecular diagnosis of the disease, we applied a set of new medical technologies, including targeted high-throughput parallel DNA sequencing (NGS) and multiplex ligation probe amplification (MLPA). Search for point mutations and small indels in RB1 gene was carried out with next generation sequencing on the Ion Torrent PGM. To detect extended deletions in the RB1 gene MLPA method was used. In a group of patients with a bilateral form of the disease, mutations in the RB1 gene were detected in 96.4% of cases. In a sample of patients with a unilateral form of the disease, genetic abnormalities were found in 31.7% of patients. MLPA technique has allowed us to identify somatic deletions in the RB1 gene in tumors of 47.6% patients and germline deletions in 4.4% patients.

This paper presents clinical data and molecular-cytogenetic description of rare microduplication 20p13 region in a patient with complex heart disease, bronchial anomaly, dysmorphic phenotypic traits, hydrocephalus. Materials and methods. A 4-month-old patient underwent a full-genomic analysis using high-resolution DNA microarrays SurePrint G3 Human Genome CGH + SNP Microarray Kit, 8 х 60K. Results. The microduplication inherited from the mother includes 46 genes. The patient’s phenotype and medical history can be partially explained by the genes involved in rearrangement. The duplication of the genes GnRH-II, OXT in the mother could affect the premature birth of the child. Genes EBF4, CENPB participate in the processes of cell division and cell migration, activation of the MAP-kinase pathway, and thus can be involved in embryogenesis. The gene ADAM33 influences the intercellular interactions in the lungs and is possibly associated with the development of bronchial abnormalities in the child. Further monitoring of the patient and a mother’s examination will make it possible to clarify the effect of microduplication 20p13 on the phenotype.

The paper gives an example of «dyagnostic Odyssee» of the patient with rare hereditary condition, Neu-Laxova syndrome. This case report emphasizes the role of Next Generation Sequencing in establishing the difficult diagnosis; also it demonstrates modern approaches to prenatal DNA analysis and obstetric care in pregnancy.