Genetic Diversity of IF?, IL1?, TLR2, and TLR8 Loci in Pulmonary Tuberculosis in Kazakhstan

Introduction. Tuberculosis (TB) is caused by bacterium Mycobacterium tuberculosis (MTB), and according to the WHO, up to 30% of world population is infected with latent TB. Pathogenesis of TB is multifactorial, and its development depends on environmental, social, microbial, and genetic factors of both the bacterium and the host. The number of TB cases in Kazakhstan has decreased in the past decade, but multidrug-resistant (MDR) TB cases are dramatically increasing. Polymorphisms in genes responsible for immune response have been associated with TB susceptibility. The objective of this study was to investigate the risk of developing pulmonary TB (PTB) associated with polymorphisms in several inflammatory pathway genes among Kazakhstani population.Methods. 703 participants from 3 regions of Kazakhstan were recruited for a case-control study. 251 participants had pulmonary TB (PTB), and 452 were healthy controls (HC). Males and females represented 42.39% and 57.61%, respectively. Of all participants, 67.4% were Kazakhs, 22.8% Russians, 3.4% Ukrainians, and 6.4% were of other origins. Clinical and epidemiological data were collected from medical records, interviews, and questionnaires. DNA samples were genotyped using TaqMan assay on 4 polymorphisms: IFN? (rs2430561) and IL1? (rs16944), TLR2 (rs5743708) and TLR8 (rs3764880). Statistical data was analyzed using SPSS 19.Results. Genotyping by IF?, IL1?, TLR2 showed no significant association with PTB susceptibility (p > 0.05). TLR8 genotype A/G was significantly higher in females (F/M – 41.5%/1.3%) and G/G in males (M/F – 49%/20.7%) (?2=161.43, p < 0.001). A significantly increased risk of PTB development was observed for TLR A/G with an adjusted OR of 1.48 (95%, CI: 0.96 - 2.28), and a protective feature was revealed for TLR8 G/G genotype (OR: 0.81, 95%, CI: 0.56 - 1.16, p = 0.024). Additional grouping by gender revealed that TLR8 G/G contributes as protective genotype (OR: 1.83, 95%, CI: 1.18 - 2.83, p = 0.036) in males of the control group.Conclusion. Results indicate that heterozygous genotype A/G of TLR8 increases the risk of PTB development, while G/G genotype may serve as protection mechanism. A/A genotype is strongly associated with susceptibility to PTB. To clarify the role of other polymorphisms in susceptibility to PTB in Kazakhstani population, further investigations are needed.

Draft genome sequences of two clinical Isolates of mycobacterium tuberculosis from sputum of Kazakh patients

Here, we report the draft genome sequences of two clinical isolates of Mycobacterium tuberculosis (MTB-476 and MTB-489) isolated from sputum of Kazakh patients

Genetic Diversity of IFγ, IL1β, TLR2, and TLR8 Loci in Pulmonary Tuberculosis in Kazakhstan

Introduction. Tuberculosis (TB) is caused by bacterium Mycobacterium tuberculosis (MTB), and according to the WHO, up to 30% of world population is infected with latent TB. Pathogenesis of TB is multifactorial, and its development depends on environmental, social, microbial, and genetic factors of both the bacterium and the host. The number of TB cases in Kazakhstan has decreased in the past decade, but multidrug-resistant (MDR) TB cases are dramatically increasing. Polymorphisms in genes responsible for immune response have been associated with TB susceptibility. The objective of this study was to investigate the risk of developing pulmonary TB (PTB) associated with polymorphisms in several inflammatory pathway genes among Kazakhstani population. Methods. 703 participants from 3 regions of Kazakhstan were recruited for a case-control study. 251 participants had pulmonary TB (PTB), and 452 were healthy controls (HC). Males and females represented 42.39% and 57.61%, respectively. Of all participants, 67.4% were Kazakhs, 22.8% Russians, 3.4% Ukrainians, and 6.4% were of other origins. Clinical and epidemiological data were collected from medical records, interviews, and questionnaires. DNA samples were genotyped using TaqMan assay on 4 polymorphisms: IFNγ (rs2430561) and IL1β (rs16944), TLR2 (rs5743708) and TLR8 (rs3764880). Statistical data was analyzed using SPSS 19. Results. Genotyping by IFγ, IL1β, TLR2 showed no significant association with PTB susceptibility (p > 0.05). TLR8 genotype A/G was significantly higher in females (F/M – 41.5%/1.3%) and G/G in males (M/F – 49%/20.7%) (χ2=161.43, p < 0.001). A significantly increased risk of PTB development was observed for TLR A/G with an adjusted OR of 1.48 (95%, CI: 0.96 - 2.28), and a protective feature was revealed for TLR8 G/G genotype (OR: 0.81, 95%, CI: 0.56 - 1.16, p = 0.024). Additional grouping by gender revealed that TLR8 G/G contributes as protective genotype (OR: 1.83, 95%, CI: 1.18 - 2.83, p = 0.036) in males of the control group. Conclusion. Results indicate that heterozygous genotype A/G of TLR8 increases the risk of PTB development, while G/G genotype may serve as protection mechanism. A/A genotype is strongly associated with susceptibility to PTB. To clarify the role of other polymorphisms in susceptibility to PTB in Kazakhstani population, further investigations are needed

WHOLE-GENOME SEQUENCING AND GENOMIC VARIANT ANALYSIS OF KAZAKH INDIVIDUALS

Introduction: Kazakhstan is the multi-ethnic country with the dominant Kazakh ethnic group in the middle of the Eurasian continent. All existing human genetic diversity datasets are only partial representations of worldwide human diversity. The information about genetic diversity of Kazakh population is lacking in these datasets. Our study aims to perform whole-genome sequencing of five healthy Kazakhs to provide insights into genetic structure and diversity of Kazakh populations in Kazakhstan. Materials and Methods: Genomic DNA of five healthy Kazakhs was isolated from peripheral blood and sequenced with Illumina HiSeq2000 to target 30-fold coverage. Reads were aligned and assembly to the human reference genome (NCBI GRCh37, hg19) and reference mitochondrial DNA rCRS (NC_012920) using Burrows-Wheeler Aligner. GATK and haplotype caller procedure has been used for genomic variants calling. All the found genomic variants were then further annotated by SIFT, PolyPhen2, SNPedia and ClinVar using ANNOVAR. Results: We sequenced and analysed the whole-genomes of ethnic Kazakh individuals with the coverage (28X-32X). From 98.85 to 99.58 % base pairs were totally mapped with properly mapped 99.06 % in average. Het/Hom and Ti/Tv ratios for each whole genome ranged from 1.35 to 1.49 and from 2.07 to 2.08, respectively. We have identified the novel variants that previously not catalogued in 1000 Genomes Project, ExAC or NCBI Reference Assembly dbSNP (snp138, avsnp138, avsnp150, hg19). Conclusion: We showed high genetic admixture of Kazakh genomes on autosomal level and similar complex heterogeneity of Central Asian populations. This whole-genome sequences information of healthy Kazakh individuals may be an important reference for biomedical studies investigating disease associations and population-wide genomic studies of ethnically diverse Central Asian region. Acknowledgments: Work was supported by grant projects #AP05134722, #AP05135430 and #AP05136106 from the Committee Science and Ministry of Education and Science at the Republic of Kazakhstan