Whole genome sequence data of Mycobacterium tuberculosis XDR strain, isolated from patient in Kazakhstan.

Drug-resistant tuberculosis (TB) is a major public health problem. Clinical Mycobacterium tuberculosis (MTB) isolate with Extensively drug-resistant tuberculosis (MTB-XDR) profile was subjected to whole-genome sequencing using a next-generation sequencing platform (NGS) Roche 454 GS FLX+ followed by bioinformatics sequence analysis. Quality of read was checked by FastQC, paired-end reads were trimmed using Trimmomatic. De novo genome assembly was conducted using Velvet v.1.2.10. The assembled genome of XDR-TB-1599 strain was functionally annotated using the PATRIC platform. Analysis of de novo assembled genome was performed using ResFinder, CARD, CASTB and TB-Profiler tools. MIRU_VNTR genotyping on 12 loci and spoligotyping have been performed for XDR-TB-1599 isolate. M. tuberculosis XDR-TB-1599 strain yielded an average read depth of 21-fold with overall 4 199 325 bp. The assembled genome contains 5528 protein-coding genes, including key drug resistance and virulence-associated genes and GC content of 65.4%. We identified that all proteins encoded by this strain contain conserved domains associated with the first-line anti-tuberculosis drugs such as rifampicin, isoniazid, streptomycin and ethionamide. TB-Profiler had higher average concordance results with phenotypic DST (drug susceptibility testing) in comparison with ResFinder, CARD, CASTB profiling to first-line (75% vs 50%) and second-line (25% vs 0%) of anti-TB drugs, correspondingly. To our knowledge, this is the first report of a highly annotated and characterized whole-genome sequence and de novo assembled XDR-TB M.tuberculosis strain isolated from a sputum of new TB case-patient from Kazakhstan performed on Roche 454 GS FLX+ platform. This report highlights an important role of whole-genome sequencing technology and analysis as an advanced approach for drug-resistance investigations of circulated TB isolates.

RYR2 sequencing reveals novel missense mutations in a Kazakh idiopathic ventricular tachycardia study cohort.

Channelopathies, caused by disturbed potassium or calcium ion management in cardiac myocytes are a major cause of heart failure and sudden cardiac death worldwide. The human ryanodine receptor 2 (RYR2) is one of the key players tightly regulating calcium efflux from the sarcoplasmic reticulum to the cytosol and found frequently mutated (<60%) in context of catecholaminergic polymorphic ventricular tachycardia (CPVT1). We tested 35 Kazakhstani patients with episodes of ventricular arrhythmia, two of those with classical CPVT characteristics and 33 patients with monomorphic idiopathic ventricular arrhythmia, for variants in the hot-spot regions of the RYR2 gene. This approach revealed two novel variants; one de-novo RYR2 mutation (c13892A>T; p.D4631V) in a CPVT patient and a novel rare variant (c5428G>C; p.V1810L) of uncertain significance in a patient with VT of idiopathic origin which we suggest represents a low-penetrance or susceptibility variant. In addition we identified a known variant previously associated with arrhythmogenic right ventricular dysplasia type2 (ARVD2). Combining sets of prediction scores and reference databases appeared fundamental to predict the pathogenic potential of novel and rare missense variants in populations where genotype data are rare.

Genetic Diversity of IFγ, IL1ß, 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 IL1ß (rs16944), TLR2 (rs5743708) and TLR8 (rs3764880). Statistical data was analyzed using SPSS 19. RESULTS: Genotyping by IFγ, IL1ß, 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.

Genetic profile and determinants of homocysteine levels in Kazakhstan patients with breast cancer.

AIM: To analyze associations between homocysteine level, MTHFR and FTO rs1477196 polymorphisms and folate status in patients with breast cancer (BC) in order to clarify determinants of hyperhomocysteinemia. PATIENTS AND METHODS: The study included 315 BC cases and 604 controls. RESULTS: The MTHFRC677T genotype was associated with an increased incidence of BC [Odds ratio (OR)=1.71; 95% Confidential interval (CI)=1.21-2.43]. The MTHFR A1298C genotype was associated with a decreased risk of BC [OR=0.68; 95% CI: 0.49-0.95]. The homocysteine level was not associated with either MTHFR C677T or A1298C, nor with FTO rs1477196, but was inversely correlated with folate status in cancer cases (p<0.0001) and tended to be higher in patients with the MTHFR 677TT genotype. The folate level (p<0.0005) was an independent predictor of hyper-homocysteinemia in patients with BC. CONCLUSION: These results suggest an important role of homocysteine in breast tumorigenesis. Further studies are warranted to investigate how combined MTHFR genotypes exert their effects on cancer susceptibility.

Mitochondrial and Y-chromosomal profile of the Kazakh population from East Kazakhstan.

AIM: To study the genetic relationship of Kazakhs from East Kazakhstan to other Eurasian populations by examining paternal and maternal DNA lineages. METHODS: Whole blood samples were collected in 2010 from 160 unrelated healthy Kazakhs residing in East Kazakhstan. Genomic DNA was extracted with Wizard genomic DNA Purification Kit. Nucleotide sequence of hypervariable segment I of mitochondrial DNA (mtDNA) was determined and analyzed. Seventeen Y-short tandem repeat (STR) loci were studied in 67 samples with the AmpFiSTR Y-filer PCR Amplification Kit. In addition, mtDNA data for 2701 individuals and Y-STR data for 677 individuals were retrieved from the literature for comparison. RESULTS: There was a high degree of genetic differentiation on the level of mitochondrial DNA. The majority of maternal lineages belonged to haplogroups common in Central Asia. In contrast, Y-STR data showed very low genetic diversity, with the relative frequency of the predominant haplotype of 0.612. CONCLUSION: The results revealed different migration patterns in the population sample, showing there had been more migration among women. mtDNA genetic diversity in this population was equivalent to that in other Central Asian populations. Genetic evidence suggests the existence of a single paternal founder lineage in the population of East Kazakhstan, which is consistent with verbal genealogical data of the local tribes.

BRCA1 and BRCA2 Gene Mutations Screening In Sporadic Breast Cancer Patients In Kazakhstan.

BACKGROUND: A large number of distinct mutations in the BRCA1 and BRCA2 genes have been reported worldwide, but little is known regarding the role of these inherited susceptibility genes in breast cancer risk among Kazakhstan women. AIM: To evaluate the role of BRCA1/2 mutations in Kazakhstan women presenting with sporadic breast cancer. METHODS: We investigated the distribution and nature of polymorphisms in BRCA1 and BRCA2 entire coding regions in 156 Kazakhstan sporadic breast cancer cases and 112 age-matched controls using automatic direct sequencing. RESULTS: We identified 22 distinct variants, including 16 missense mutations and 6 polymorphisms in BRCA1/2 genes. In BRCA1, 9 missense mutations and 3 synonymous polymorphisms were observed. In BRCA2, 7 missense mutations and 3 polymorphisms were detected. There was a higher prevalence of observed mutations in Caucasian breast cancer cases compared to Asian cases (p<0.05); higher frequencies of sequence variants were observed in Asian controls. No recurrent or founder mutations were observed in BRCA1/2 genes. There were no statistically significant differences in age at diagnosis, tumor histology, size of tumor, and lymph node involvement between women with breast cancer with or without the BRCA sequence alterations. CONCLUSIONS: Considering the majority of breast cancer cases are sporadic, the present study will be helpful in the evaluation of the need for the genetic screening of BRCA1/2 mutations and reliable genetic counseling for Kazakhstan sporadic breast cancer patients. Evaluation of common polymorphisms and mutations and breast cancer risk in families with genetic predisposition to breast cancer is ongoing in another current investigation.