[A clinical and genetic analysis of risk factors for the development of acute and chronic cerebral ischemia]. / Kliniko-geneticheskii analiz faktorov riska razvitiia ostroi i khronicheskoi ishemii golovnogo mozga.

To study the association between polymorphic markers in the ACE, SERPINE1, FGB, F5, F7, F12, GP1BA, GPIIIa, MTHFR, CYP11B2, PON1, PON2, NOS2, NOS2, HIFla, LTA, ALOX5AP genes and clinical characteristics of acute and chronic forms of circulatory disorders of the brain. MATERIAL AND METHODS: The analysis of polymorphic variants in ACE, FGB, F5, F7, F12, GP1BA, GPIIIa, SERPINE1, MTHFR, CYP11B2, PON1, PON2, NOS2, NOS3, PDE4D, HIF1a, LTA, ALOX5AP in 81 patients with chronic cerebral ischemia (CCI) and 69 patients with ischemic stroke (IS), and their interrelation with clinical manifestations of disease were investigated. RESULTS AND CONCLUSION: The association between the T/T genotype of the PDE4D SNP 83C>T polymorphism and a rapid progression of hypertensive disease (GB) was revealed (OR=6.22, CI=1.86-20.79, p=0.0036) in the group of patients with CCI. The association of the allele D and the DD genotype of the ACE (I>D, rs1799752) with cardioembolic stroke (OR=2.67, 95% CI=1.23-5.8, p=0.02 and OR=7.14, 95% CI=1.72-29.69, p=0.0057) was found. When comparing subgroups of patients with different degrees of stenosis of brachiocephalic arteries (BCA), the association of the allele C and the TC genotype of the GP1BA (rs2243093, -5T/C) with BCA occlusion and expressed hemodynamically significant stenosis (>75%) was revealed (OR=3.39, 95% CI=1.12-10.25, p=0.03 and OR=4.44, 95% CI=1.27-15.54, p=0.023, respectively). Thus, polymorphic markers in PDE4D, ACE, GP1BA in combination with certain clinical characteristics are risk factors for the progression of CCI and development of IS.

[Multiplex Genotyping of Allelic Variants of Genes Involved in Metabolizing Antileukemic Drugs].

A biochip, primer set, and genotyping protocol were developed to simultaneously address 16 single nucleotide polymorphisms in antileukemic drug metabolism genes, including TPMT, ITPA, MTHFR, SLCO1B1, SLC19A1, NR3C1, GRIA1, ASNS, MTRR, and ABCB1. The genotyping procedure included a one-round multiplex polymerase chain reaction (PCR) with simultaneous incorporation of a fluorescent label into the PCR product and subsequent hybridization on a biochip with immobilized probes. The method was used to test 65 DNA samples of leukemia patients. Fluorescence signal intensity ratios in pairs of wild-type and respective mutant sequence probes were analyzed for all polymorphic markers and demonstrated high accuracy of genotyping. The reliability of genotype determination using the biochip was confirmed by direct Sanger sequencing.

[Allelic variants of immune response genes in children with infectious complications during the treatment of acute leukemia].

Infectious complications that arise during the treatment of children with acute leukemia with chemotherapeutic agents at high doses represent a serious problem in oncohematology. To find genetic conditions that may lead to the development of postchemotherapy infections, the genomes of 12 children with acute leukemia who had severe infectious complications during therapy were examined. At the same time, the coding regions of 17 genes involved in the regulation of the immune response were determined by massive parallel sequencing. The analysis revealed 39 nonsynonymous SNPs that lead to amino acid substitutions, including the following informative genetic markers: PTPN22 c.1858C>T (rs2476601), TLR4 c.896A>G (rs4986790) and TLR4 c.1196C>T (rs4986791), IL7R c.197T>C (rs1494555) and IL7R c.412G>A (rs1494558). The results of massive parallel sequencing were validated by Sanger sequencing. The identification of genetic markers associated with the predisposition to infectious complications may allow one to assess the individual risk of the severe infection development in children with acute leukemia during the treatment with chemotherapeutic agents and to begin the development of personalized approaches to anticancer therapy.

[Biological microchip for establishing the structure of fusion transcripts involving MLL in children with acute leukemia].

MLL is involved in fusion genes with more than 100 partner genes, approximately 80 of which have been characterized at the molecular level. MLL fusion genes are often found in infants (60-80% of acute lymphoblastic leukemia (ALL) cases and 40-50% of acute myeloblastic leukemia (AML) cases) and are appreciably rarer (8-10%) in children older than 1 year of age. MLL rearrangements are important markers in diagnosis and treatment choice. To identify the partner gene is of primary importance for prognosis and minimal residual disease monitoring. The structure of the fusion gene, including localization of the MLL breakpoints, is also informative. A method was developed to examine the fusion transcripts in order to identify the partner gene among the six most common ones and to establish the exon structure of the rearranged MLL. The method includes a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify and to fluorescently label a fusion transcript fragment and subsequent hybridization of the product on a biological microchip with immobilized oligonucleotides complementary to exons of MLL and its partner genes AFF1, MLLT1, MLLT3, MLLT4, MLLT10, and ELL. Hybridization results were verified by sequencing the RT-PCR products and, in some cases, performing long-distance inverse PCR (LDI-PCR). The study involved 38 bone marrow samples from ALL patients (including 33 children younger than 1 year of age) and 15 samples from AML patients (including 10 from children younger than 1 year of age). The main partner genes were AFF1 (49%), MLLT1 (27%), MLLT3 (12%), and MLLT10 (12%) in ALL and MLLT3 (80%), MLLT10 (10%), and MLLT4 (10%) in AML. Fusion gene transcripts most commonly included MLL exon 11 (58% of ALL cases and 50% of AML cases), suggesting a breakpoint in MLL intron 11.

[Association study of polymorphic markers of F12, PON1, PON2, NOS2, PDE4D, HIF1a, GPIba, CYP11B2 genes with ischemic stroke in Russian patients].

Allele and genotype frequencies of 10 single nucleotide polymorphisms in F12, PON1, PON2, NOS2, PDE4D, HIF1a,GPIba, CYP11B2 genes were studied in a group of Russian patients with ischemic stroke (IS) from central regions of the Russian Federation and healthy donors matched for sex, age and ethnicity. The genotyping procedure included the amplification of selected DNA sequences with the following hybridization of fluorescently-labeled regions with allele-specific DNA-probes immobilized on a biochip. An analysis of allele and genotype frequencies for each gene in IS patients and controls did not reveal any significant differences. The pair-wise comparison of genes demonstrated that the frequency of the combination PON1A/-x PON2 GG was higher in the group of patients (p=0.044, OR=3.4 95% CI 1.06 − 10.4) compared to the controls and, thus, was associated with the higher risk for stroke.