A Complex of Pyrosequencing-Based Methods for Detection of Somatic Mutations in Codons 600 and 601 of the BRAF gene.

The aim of the study is to develop methods for the differentiation of mutations in the BRAF codon 600 and to increase the sensitivity of the K601E mutation detection. Materials and Methods: The nucleotide sequence of the BRAF codons 592-602 was identified using the PyroMark Q24 genetic analysis system. The mutations search in codon 600 was conducted using the 600-S primer in line with the following order of adding nucleotides: GCTGTCАTCTGCTAGCTAGAC (corresponding to nucleotides 1799-1786). The K601E mutation was detected using the 601-S primer in line with the following order of nucleotide addition: GCTACTCACTGTAG (corresponding to nucleotides 1801-1793). The analytical characteristics of the proposed methods for somatic mutations' detection were determined using dilutions of plasmid DNA samples containing the BRAF gene region without mutations or with one of the following mutations: V600E, V600R, V600K, V600M, and K601E. Validation was performed on 132 samples of biological material obtained from the thyroid nodules. Results: The developed methods allow to determine 2% of the V600E or V600M mutations, 1% of the V600K and V600R mutations, and 3% of the K601E mutations in samples with high DNA concentration; it is also possible to confidently detect at least 5% of the mutant allele for all mutations in low concentration samples (less than 500 copies/PCR). During biological material testing, 53 samples with the V600E mutation were detected; the proportion of the mutant allele was 4.9-50.0%. Conclusion: A complex of methods for determination of the nucleotide sequence of the BRAF codons 592-601 and the algorithm for testing samples and analyzing mutations in the BRAF codons 600-601 was developed. The method provides sufficient sensitivity to detect frequent mutations in codons 600 and 601 and allows them to be precisely differentiated.

[A comparative analysis of allele frequencies of rs1801133 and rs1801131 of MTHFR in patients with stroke and healthy people from the Moscow region]. / Sravnitel'nyi analiz chastot allel'nykh variantov rs1801133 i rs1801131 gena MTHFR v vyborke patsientov, perenesshikh ishemicheskii insul't, i u zdorovogo naseleniia v Moskovskom regione.

AIM: To study genetic characteristics of the population of the Moscow region and analyze the association of rs1801133 and rs1801131 of MTHFR with the risk of ischemic stroke (IS). MATERIAL AND METHODS: A sample of 170 and 115 patients with atherothrombotic and cardioembolic subtypes of IS and 360 residents of the Moscow region without IS were examined. MTHFR alleles were determined by a multiplex real-time polymerase chain reaction. RESULTS AND CONCLUSION: No association between the frequencies of MTHFR alleles and the risk of ischemic stroke was found. The comparison of allele frequencies with those in Caucasian populations published in the dbSNP (NCBI) and 1000 Genomes Project databases revealed significant differences for rs1801133 from the EUR 1000 Genomes Project. The allele frequency data for MTHFR could increase the accuracy and reliability of the individual risk calculation for multifactorial diseases in the Russian population.

[Complex assessment of the contribution of genetic factors to the risk of ischemic stroke]. / Kompleksnaia otsenka vklada geneticheskikh faktorov v razvitie ishemicheskogo insul'ta.

AIM: To develop a method of the complex assessment of genetic risk for ischemic stroke (IS) and evaluate its effectiveness. MATERIAL AND METHODS: 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. RESULTS AND CONCLUSION: 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 (p <0,05). 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.

[A method for determination of Neisseria meningitidis serogroup A, B, C and W by real-time PCR].

AIM: Development and testing of a real-time PCR method for detection of Neisseria meningitiis serogroup A, B, C and W DNA. MATERIALS AND METHODS: Reference strains and 187 samples of cerebrospinal fluid (CSF) from meningocci meningitis patients were used in the study. Multiplex PCR was carried out in an instrument with 5 channels of fluorescent detection: RESULTS: Analysis of specific serogroup loci of the genome and design of oligonucleotides for the detection of DNA of all the capsule meningococci and 4 serogroups in particular was carried out. PCR conditions were optimized; specificity was shown and analytical sensitivity was evaluated using reference strains. DNA of the following serogroups was detected during study of clinical CSF samples: A--in 103 samples (55%), B--in 45 (24%), C--in 30 (16%), W--in 5 (3%). Only DNA of meningococci capstle gene ctrA was found in 4 samples; presumably, they contained DNA of other serogroups. Multilocus sequence-typing and detection of antigenic determinants of PorA and FetA genes for 27 DNA samples of group A menincococci as well as DNA of 5 group W meningococci and 4 ungroupable was carried out. CONCLUSION: The method proposed allows to carry out serogrouping of no less than 95% of strains or DNA samples isolated from CSF of meningococci infection patients. Combined with other recommended non-cultural methods of genotyping, it may be useful for complex characteristics of pathogenic meningococci.

[The detection of activating somatic mutations in gene KRAS using pyrosequencing technique].

The technique to detect all possible variants of mutations in 12, 13 and 15 codons of gene KRAS was developed on the basis of the pyrosequencing technology. The analytical characteristics of the developed technique were identified. The limit of detection for mutations G34T, G35A and G38A detected on the cloned control samples consisted 3%. The limit of blank for various mutations consisted from 0.3% to 4.1%. The system was tested on clinical samples. The 7 different types of mutations were identified and detected in quantitative format. No discrepancy of pyrosequencing data with results of sequencing according Sanger was established.

[Polymorphism of ABCB1 and ABCG2 genes encoding drug transporters and their investigation by pyrosequencing].

Published data on the effect of transporter propeins of the ABC family in the features of drug pharmacokinetics in the human organism are reviewed. Clinical significance of mononucleotide polymorphisms in ABCB1 and ABCG2 genes is analyzed. A set of genetic tests based on pyrosequencing for determing the allele state in rs1128503 (1236 T > C), rs2032582 (2677T > A/G), rs1045642 (3435 T > A/C), rs2231142 (421C > A), and rs72552713 (376 C > T) polymorphisms in ABCB1 and ABCG2 genes has been developed and verified. These tests can be used in both research work and clinical practice for calculating recommended doses of various drugs, predicting their therapeutic efficacy, and determining groups of risk with respect to the developent of undesired secondary reactions.

[Allele polymorphism of microsatellite loci in pea Pisum sativum L. lines, varieties, and mutants].

Interlinear polymorphism at 23 microsatellite loci was studied in 40 Pisum sativum lines, varieties, and mutants and proved to be high, 61.6% on average. Varieties bred for different end uses substantially differed in the extent of polymorphism and allele composition. Polymorphism of microsatellite loci was shown to be suitable for developing passports of industrial pea varieties.

[The study of the genetic effects in generation of pea plants cultivated during the whole cycle of ontogenesis on the board of RS ISS].

Results of studies on growth and development of offspring of two genetically marked dwarf pea lines planted during the whole ontogenesis cycle in the Lada space greenhouse on board of Russian Segment of International Space Station (RS ISS) are presented. The offspring of M1 and M2 plants grown from seeds formed during space flight was examined under conditions of Earth-based. Cultivation. It had been shown that growth and developmental characteristics, frequency of chromosome aberrations in primary root meristem and level of molecular polymorphism revealed in individual plants via RAPD method show no significant differences between offspring of "space-grown" and control seeds.

[Analysis of DNA polymorphism in a relict Uralian species, yellow foxglove (Digitalis grandiflora Mill.), using RAPD and ISSR markers].

Genetic polymorphism of the Uralian relict plant species, yellow foxglove Digitalis grandiflora Mill. (family Scrophulariaceae), was examined using RAPD and ISSR techniques. A total of 149 RAPD and 74 ISSR markers were tested. The indices characterizing polymorphism and genetic diversity were calculated. The data obtained pointed to a high level of genetic variation of D. grandiflora (P95 = 65%). The cenopopulation examined was weakly differentiated with most of genetic diversity accounted by within-population differentiation.