Blocks identical by descent in the genomes of the indigenous population of Siberia demonstrate genetic links between populations.

The gene pool of the indigenous population of Siberia is a unique system for studying population and evolutionary genetic processes, analyzing genetic diversity, and reconstructing the genetic history of populations. High ethnic diversity is a feature of Siberia, as one of the regions of the peripheral settlement of modern human. The vast expanses of this region and the small number of aboriginal populations contributed to the formation of significant territorial and genetic subdivision. About 40 indigenous peoples are settled on the territory of the Siberian historical and ethnographic province. Within the framework of this work, a large-scale population study of the gene pool of the indigenous peoples of Siberia was carried out for the first time at the level of high-density biochips. This makes it possible to fill in a significant gap in the genogeographic picture of the Eurasian population. For this, DNA fragments were analyzed, which had been inherited without recombination by each pair of individuals from their recent common ancestor, that is, segments (blocks) identical by descent (IBD). The distribution of IBD blocks in the populations of Siberia is in good agreement with the geographical proximity of the populations and their linguistic affiliation. Among the Siberian populations, the Chukchi, Koryaks, and Nivkhs form a separate cluster from the main Siberian group, with the Chukchi and Koryaks being more closely related. Separate subclusters of Evenks and Yakuts, Kets and Chulyms are formed within the Siberian cluster. Analysis of SNPs that fell into more IBD segments of the analyzed populations made it possible to compile a list of 5358 genes. According to the calculation results, biological processes enriched with these genes are associated with the detection of a chemical stimulus involved in the sensory perception of smell. Enriched for the genes found, molecular pathways are associated with the metabolism of linoleic, arachidonic, tyrosic acids and by olfactory transduction. At the same time, an analysis of the literature data showed that some of the selected genes, which were found in a larger number of IBD blocks in several populations at once, can play a role in genetic adaptation to environmental factors.

[The Role of Natural Selection in the Formation of the Genetic Structure of Populations by SNP Markers in Association with Body Mass Index and Obesity].

Obesity is one of the major challenges in modern society. More than a third of the world's population suffers froms overweight. This phenotype affects the quality of life and is associated with cardiovascular diseases, diabetes, cancer and reproductive disorders. The population variability of allele frequencies of 26 single nucleotide polymorphisms, in association with obesity and body mass index, according to data from genome-wide association studies (GWASs) is discussed in this study. Genetic variability was analyzed in populations of Northern Eurasia and populations from the human genome diversity project (HGDP). The population samples are characterized by high genetic diversity that correlates with climatic and geographical parameters. The results of the test for searching for natural selection signals revealed a selection effect for rs1167827 of the HIP1 gene, rs7138803 and rs7164727 located in the intergenic region, rs7141420 of the NRXN3 gene, rs7498665 of the SH2B1 gene, and rs7903146 of the TCF7L2 gene.

[A rare variant in the sortilin-related receptor 1 gene is associated with declined cognitive functions in the elderly]. / Redkii variant v gene sortilinpodobnogo retseptora 1: sviaz' s pokazateliami kognitivnykh funktsii u pozhilykh.

AIM: To estimate the association of rs11218343 in the sortilin-related receptor 1 (SORL1) gene with cognitive performance in the elderly and with Alzheimer's disease (AD) in the Russian population. MATERIAL AND METHODS: A sample included 586 elderly people (mean age 70.9±5.7 years) without AD diagnosis and 100 patients with late-onset AD (mean age 72.1±7.8 years) from the Tomsk population. SORL1 rs11218343 was genotyped using PCR and MALDI-TOF mass spectrometry. Cognitive performance in the sample of elderly without AD was assessed by Montreal Cognitive Assessment (MoCA) test. RESULTS: Allele frequencies of the SORL1 polymorphism were not significantly different between the elderly without AD and AD patients. However mean MoCA score in the carriers of the rare allele (19.00±6.61) was significantly lower than in homozygotes for the common variant (22.25±3.89) (F=4.97; p=0.026). CONCLUSION: The rare variant in SORL1 gene previously associated with AD in genome-wide association studies and meta-analyses was associated with lower total МоСА scores in the random sample of elderly people that suggests declined cognitive functions in the carriers of this variant in elderly.

[Association study of genetic markers of schizophrenia and its cognitive endophenotypes].

A replicative analysis of associations of 15 SNPs located in the regions of 11 genes (TCF4, VRK2, NOTCH4, ZNF804A, AGBL1, RELN, ZFP64P1, KCNB2, CSMD1, CPVL, NRIP1) and three intergenic regions (SLCO6A1/LINCOO491, LOC105376248/LOC105376249, SPA17/NRGN) with schizophrenia was conducted in the Russian population of the Siberian region. These SNPs were previously identified in genome-wide association studies (GWAS) of schizophrenia and cognitive abnormalities. The present study confirmed associations of KCNB2 rs2247572, CSMD1 rs2616984, and intergenic rs12807809 located in SPA17/NRGN with schizophrenia. It was established that the frequency of the CSMD1 rs2616984 G/G genotype was higher in patients compared to the control group (OR = 1.73; CI: 1.14­2.62; р = 0.0337). The frequencies of the KCNB2 rs2247572 TT genotype (OR = 0.41; CI: 0.20­0.87; р = 0.0485) and intergenic rs12807809 CT genotype located in SPA17/NRGN (OR = 0.70; CI: 0.53­0.94; р = 0.0464) were significantly decreased in patients compared to the control group.

[Variability and Identification Power 60 X-Cromosome in Two Native Siberian Populations].

Genetic diversity of 60 X-chromosome single nucleotide polymorphisms (XSNPid panel) in populations of Siberian Tatars and Tuvinians is described. A close spectrum of allele frequencies and a low level of their genetic differentiation (Gst = 0.021) is revealed. High discriminating power of the XSNPid panel in populations under study is demonstrated. The random matching probability (MP) of multilocus genotypes in males is 1.12 x 10⁻¹8 in Siberian Tatars and 7.77 x 10⁻¹6 in Tuvans. In females, MP is several orders of magnitude lower: 1.51 x 10⁻²5 in Siberian Tatars and 1.83 x 10⁻²³ in Tuvinians.

[Panel of X-linked single-nucleotide polymorphic markers for DNA identification (XSNPid) based on multiplex genotyping by multilocus PCR and MALDI-TOF mass spectrometry].

Human genetic markers linked with the X chromosome (X-linked) are used in the field of population and medical genetics, as well as for DNA identification of individuals in forensic science and forensic medicine. We proposed an XSNPid panel that consists of 66 unlinked single nucleotide X chromosome markers and developed a protocol for their multiplex genotyping using multilocus PCR and MALDI-TOF mass spectrometry. The XSNPid panel is genotyped within two multiplexes (36 and 30 markers). The developed protocol provides an efficient genotype reading; the fraction of determined genotypes is 98.29%. The high level of gene diversity (0.461) for the X-linked SNPs included in the panel is characteristic of the Russian population. A total of 63 out of 66 markers that provide a high efficiency of genotyping and independent inheritance are suitable for DNA identification purposes. The XSNPid panel is characterized by a very high discriminating ability when studying the Russian population. The probability of genotype coincidence in two unrelated individuals is 9 × 10^(-27) for women and 2 × 10^(-18) for men. Also, the XSNPid panel has a greater multiplex capacity in addition to a higher discriminating ability compared to the other closest analogues of the X chromosome SNP sets, which makes it more cost effective and less time consuming. The XSNPid panel is a convenient tool, not only for individual DNA identification, but also for population genetic studies.

[Prevalence of gene polymorphisms associated with immune-dependent diseases in the populations of North Eurasia].

The data on distribution of genetic diversity in gene polymorphisms associated with autoimmune and allergic diseases and with regulation of immunoglobulin E and cytokines levels in 26 populations of the Northern Eurasia is presented. Substantial correlation between the values of average expected heterozygosity by 44 gene polymorphisms with climatic and geographical factors has not been revealed. Clustering of population groups in correspondence with their geographic locations is observed. The degree of gene differentiation among populations and the selective neutrality of gene polymorphisms have been assessed. The results of our work evidence the substantial genetic diversity and differentiation of human populations by studied genes.

[Genetic diversity of X-linked STR-markers in Siberian populations].

X-chromosome markers are informative tool for studying of the genetic diversity in human populations and become useful for DNA identification when certain complex kinship cases need to be unraveled. In this work, we present population genetic data of 10 X-chromosome STRs (DXS8378, DXS9898, DXS8377, HPRTB, GATA172D05, DXS7423, DXS6809, DXS7132, DXS101 and DXS6789). Average level of expected heterozygosity (He) in populations under study was 0.73. Total level of genetic differentiation for 10 studied populations was relatively low (Fst = 0.031 comparing to autosomal and Y-chromosomal markers. Allele frequencies and parameters of forensic interest for panel of X-STRs were calculated. The overall values of PDf and PDm are 0.9999999997, 0.999998 respectively. The overall level of genetic differentiation for 10 population (Fst) is 0.03186.

[Replicative study of susceptibility to childhood-onset schizophrenia in Kazakhs].

This paper reports the results of replicative analysis of associations of 15 SNPs in a region of 14 genes previously identified in genome-wide association studies (GWAS) with early-onset schizophrenia in Kazakhs. An association of early-onset schizophrenia with genetic markers in three genes (VRK2, KCNB2, and CPVL) was found. An association of rs2312147 in the VRK2 gene with schizophrenia was also previously reported in the Chinese population, so this marker may be considered as possibly race-specific. Two groups consisting of four and six genes demonstrating intergenic epistatic interactions were revealed by multifactor dimensionality reduction methods. The gene ontologies of 14 studied genes were reduced to variants of one molecular function (peptidase activity) and one biological process (positive regulation of biosynthesis processes). Bioinformatic analysis of the protein-protein interactions of products of the genes under study demonstrates that the products of six out of 14 genes may be involved in a single interrelated network, the major connecting link of which is represented by their ubiquitination by the UBC protein.

[Association of the genenetic polymorphism of cytokines and their receptors with climate and geographic factors in human populations].

The variability of eight polymorphic variants of the IL4, IL4R, IL10, IL13, IL12A, and IL12RB2 genes encoding key cytokinesand their receptors in 57 world populations has been assessed. A correlation between the allele frequency distribution of the examined genes and climatic and geographic factors was observed.