HLA-A, HLA-B, and HLA-DRB1 allele distribution in a large Armenian population sample

High-Resolution HLA-DRB1 Allele Frequencies in a Romanian Cohort of Stem Cell Donors

The goal of the current study was to determine the high-resolution frequencies of the HLA-DRB1 alleles among the analyzed Romanian cohort of healthy stem cell donors. Using Next Generation Sequencing (NGS), we estimated class II HLA-DRB1 allele frequencies to a 6-digit resolution through HLA typing in a Romanian cohort of healthy individuals. The study for HLA genotyping included 420 willing donors from the National Registry of Voluntary Hematopoietic Stem Cell Donors (RNDVCSH). In 2020 and 2021, peripheral blood samples were collected and transported to the Fundeni Clinical Institute. We used the Immucor Mia Fora NGS MFlex kit for HLA genotyping. Forty-one different alleles were detected in 420 analyzed samples, out of which the most frequent HLA-DRB1 alleles were DRB1*16:01:01 (12.6%), DRB1*11:04:01 (12.1%) and DRB1*03:01:01 (12%). The HLA-DRB1*11:01:02 and -DRB1*08:04:01, -DRB1*05:01:01, -DRB1*13:05:01, -DRB1*14:07:01, -DRB1*09:01:02, -DRB1*11:02:01, -DRB1*04:07:01, -DRB1*15:03:01, -DRB1*03:02:01, -DRB1*04:06:02, -DRB1*04:08:01, -DRB1*14:05:01 were identified only once. The results revealed similarities with countries belonging to the Eastern Europe, the Balkans and the Caucasus regions. Further studies on larger Romanian cohorts are needed for confirming the current results.

DNA methylation of ITGB2 contributes to allopurinol hypersensitivity

BACKGROUNDS

HLA-B*58:01 allele was strongly associated with allopurinol induced severe cutaneous adverse drug reaction (SCAR). However, HLA-B genotype is not sufficient to predict the occurrence of allopurinol-induced SCAR.

OBJECTIVE

To discover DNA methylation markers for allopurinol-induced SCAR which may improve the prediction accuracy of genetic testing.

STUDY DESIGN

The study was designed as a retrospective case-control clinical study in multicenter hospitals across Taiwan, Mainland China, Malaysia and Canada. 125 cases of allopurinol-induced SCAR patients and 139 cases of allopurinol tolerant controls were enrolled in this study during 2005 to 2021.

RESULTS

The results of genome-wide DNA methylation assay of 62 patients revealed that ITGB2 showed strong discriminative ability of allopurinol-induced SCAR in both HLA-B*58:01 positive and negative patients with AUC value of 0.9364 (95% CI 0.8682-1.000). In validation study, significant hypermethylation of ITGB2 were further validated in allopurinol-induced SCAR patients compared to tolerant controls, especially in those without HLA-B*58:01(AUC value of 0.8814 (95% CI 0.7121-1.000)). Additionally, the methylation levels of 2 sites on ITGB2 were associated with SCAR phenotypes. Combination of HLA-B*58:01 genotyping and ITGB2 methylation status could improve the prediction accuracy of allopurinol-induced SCAR with the AUC value up to 0.9387 (95% CI 0.9089-0.9684), while the AUC value of HLA-B*58:01 genotyping alone was 0.8557 (95% CI 0.8030-0.9083).

CONCLUSIONS

Our study uncovers differentially methylated genes between allopurinol-induced SCAR patients and tolerant controls with positive or negative HLA-B*58:01 allele and provides the novel epigenetic marker that improves the prediction accuracy of genetic testing for prevention of allopurinol-induced SCAR.

HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies in Lebanese and their relatedness to neighboring and distant populations

BACKGROUND

This study examined the origin of present-day Lebanese using high-resolution HLA class I and class II allele and haplotype distributions. The study subjects comprised 152 unrelated individuals, and their HLA class I and class II alleles and two-locus and five-locus haplotypes were compared with those of neighboring and distant communities using genetic distances, neighbor-joining dendrograms, correspondence, and haplotype analyses. HLA class I (A, B, C) and class II (DRB1, DQB1) were genotyped at a high-resolution level by PCR-SSP.

RESULTS

In total, 76 alleles across the five HLA loci were detected: A*03:01 (17.1%), A*24:02 (16.5%), B*35:01 (25.7%), C*04:01 (25.3%), and C*07:01 (20.7%) were the most frequent class I alleles, while DRB1*11:01 (34.2%) and DQB1*03:01 (43.8%) were the most frequent class II alleles. All pairs of HLA loci were in significant linkage disequilibrium. The most frequent two-locus haplotypes recorded were DRB1*11:01 ~ DQB1*03:01 (30.9%), B*35:01-C*04:01 (20.7%), B*35:01 ~ DRB1*11:01 (13.8%), and A*24:02 ~ B*35:01 (10.3%). Lebanese appear to be closely related to East Mediterranean communities such as Levantines (Palestinians, Syrians, and Jordanians), Turks, Macedonians, and Albanians. However, Lebanese appear to be distinct from North African, Iberian, and Sub-Saharan communities.

CONCLUSIONS

Collectively, this indicates a limited genetic contribution of Arabic-speaking populations (from North Africa or the Arabian Peninsula) and Sub-Saharan communities to the present-day Lebanese gene pool. This confirms the notion that Lebanese population are of mixed East Mediterranean and Asian origin, with a marked European component.

Molecular Analysis of SARS-CoV-2 Lineages in Armenia

The sequencing of SARS-CoV-2 provides essential information on viral evolution, transmission, and epidemiology. In this paper, we performed the whole-genome sequencing of SARS-CoV-2 using nanopore and Illumina sequencing to describe the circulation of the virus lineages in Armenia. The analysis of 145 full genomes identified six clades (19A, 20A, 20B, 20I, 21J, and 21K) and considerable intra-clade PANGO lineage diversity. Phylodynamic and transmission analysis allowed to attribute specific clades as well as infer their importation routes. Thus, the first two waves of positive case increase were caused by the 20B clade, the third peak caused by the 20I (Alpha), while the last two peaks were caused by the 21J (Delta) and 21K (Omicron) variants. The functional analyses of mutations in sequences largely affected epitopes associated with protective HLA loci and did not cause the loss of the signal in PCR tests targeting ORF1ab and N genes as confirmed by RT-PCR. We also compared the performance of nanopore and Illumina short-read sequencing and showed the utility of nanopore sequencing as an efficient and affordable alternative for large-scale molecular epidemiology research. Thus, our paper describes new data on the genomic diversity of SARS-CoV-2 variants in Armenia in the global context of the virus molecular genomic surveillance.

HLA-C*04:01 Affects HLA Class I Heterozygosity and Predicted Affinity to SARS-CoV-2 Peptides, and in Combination With Age and Sex of Armenian Patients Contributes to COVID-19 Severity

The novel SARS-CoV-2 coronavirus infection has become a global health concern, causing the COVID-19 pandemic. The disease symptoms and outcomes depend on the host immunity, in which the human leukocyte antigen (HLA) molecules play a distinct role. The HLA alleles have an inter-population variability, and understanding their link to the COVID-19 in an ethnically distinct population may contribute to personalized medicine. The present study aimed at detecting associations between common HLA alleles and COVID-19 susceptibility and severity in Armenians. In 299 COVID-19 patients (75 asymptomatic, 102 mild/moderate, 122 severe), the association between disease severity and classic HLA-I and II loci was examined. We found that the advanced age, male sex of patients, and sex and age interaction significantly contributed to the severity of the disease. We observed that an age-dependent effect of HLA-B*51:01 carriage [odds ratio (OR)=0.48 (0.28-0.80), Pbonf <0.036] is protective against severe COVID-19. Contrary, the HLA-C*04:01 allele, in a dose-dependent manner, was associated with a significant increase in the disease severity [OR (95% CI) =1.73 (1.20-2.49), Pbonf <0.021] and an advancing age (P<0.013). The link between HLA-C*04:01 and age was secondary to a stronger association between HLA-C*04:01 and disease severity. However, HLA-C*04:01 exerted a sex-dependent differential distribution between clinical subgroups [females: P<0.0012; males: P=0.48]. The comparison of HLA-C*04:01 frequency between subgroups and 2,781 Armenian controls revealed a significant incidence of HLA-C*04:01 deficiency in asymptomatic COVID-19. HLA-C*04:01 homozygous genotype in patients blueprinted a decrease in heterozygosity of HLA-B and HLA class-I loci. In HLA-C*04:01 carriers, these changes translated to the SARS-CoV-2 peptide presentation predicted inefficacy by HLA-C and HLA class-I molecules, simultaneously enhancing the appropriate HLA-B potency. In patients with clinical manifestation, due to the high prevalence of HLA-C*04:01, these effects provided a decrease of the HLA class-I heterozygosity and an ability to recognize SARS-CoV-2 peptides. Based on our observations, we developed a prediction model involving demographic variables and HLA-C*04:01 allele for the identification of potential cases with the risk of hospitalization (the area under the curve (AUC) = 86.2%) or severe COVID-19 (AUC =71%).

Diversity of HLA class I and class II alleles in Iran populations: Systematic review and Meta-Analaysis

The human leukocyte antigen (HLA) system plays an essential role in the peptides antigen presentation and more regulation of immune responses. Regarding all HLA molecules' associations with various diseases and their clinical utilities in understanding drug reactions or prediction of transplantation outcome, there is a need for much more extensive HLA data generated from Asian countries.

METHOD

A comprehensive search was conducted in electronic databases between 1990 and 2021 to identify relevant articles to HLA frequency in the normal Iranian population. Two independent reviewers screened and selected the eligible studies. After data extraction, the meta-analysis was performed using STATA version 14. The overall frequencies and their 95% confidence intervals (CIs) were obtained using the random-effects model.

RESULTS

Among 1141 studies 78 were eligible for this study and the sample sizes varied from 14 to 15,600. The most frequent alleles of HLA class I were HLA-A*02 (22%; 95%CI: 20-24%; I² = 88.63%), -B*35 (18%; 95%CI: 16-21%; I² = 90.95%), -C*12 (18%; 95%CI: 13-22%; I² = 89.51%). HLA-DQA1*01 (42%; 95%CI: 40-44%; I² = 56.80%), -DQB1*03 (38%; 95%CI: 35-42%; I² = 92.38%), and -DRB1*11 (24%; 95%CI: 22-26%; I² = 90.72%) were the most frequent alleles of HLA class II in Iran.

DISCUSSION

Our meta-analysis results point out that the comprehensive report of HLA allele frequency in the Iranian population could be helpful as reference data for planning and managing transplantation and immune disease treatment in Iran.

HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies and phylogenetic analysis of Bahraini population

The origin of Arab-speaking population is classified according to their geographical location, ethnic background, and historical influx of nearby and distant populations. Data on HLA class I and class II loci in (Arabian Peninsula) Bahraini population are lacking. We analyzed HLA genetic profile of Bahrainis with neighboring communities, and with Levantines, North Africans, Sub-Saharans, Europeans, and Asians, using genetic distances, neighbor-joining dendrograms, correspondence and haplotype analysis. HLA class I and class II genotyping were done by high resolution PCR-SSP in 175 Bahraini subjects. In total, 19 HLA-A, 33 HLA-B, 15 HLA-C, 14 DRB1 and 7 DQB1 alleles were identified. The most common class I alleles were A*02:01:01 (18.3%), A*01:01:01(15.4%), B*35:01:02 (12.9%), C*12:01:01 (15.1%), and C*04:01:01 (14.9%), while DRB1*03:01:01 (18.0%), DQB1*02:01:01 (29.1%), and DQB1*05:01:01 (24.9%) were the most frequent class II alleles. Significant linkage disequilibrium was seen between all HLA loci pairs. DRB1*03:01:01-DQB1*02:01:01 (15.18%) was the most frequent two-locus haplotype. Significant negative Fnd values were observed, indicating balancing selection at studied loci. Bahrainis appear to be related to Western Mediterranean (North Africans, Iberians and French), but relatively distinct from Levantines (Palestinians, Lebanese, and Jordanians) and Sub-Saharans. This indicates limited genetic contribution of Levantine Arabs and Sub-Saharans to the Bahraini gene pool.

HLA-A, -B, -C, -DRB1, -DQA1, and -DQB1 allele and haplotype frequencies defined by next generation sequencing in a population of East Croatia blood donors

Next-generation sequencing (NGS) is increasingly used in transplantation settings, but also as a method of choice for in-depth analysis of population-specific HLA genetic architecture and its linkage to various diseases. With respect to complex ethnic admixture characteristic for East Croatian population, we aimed to investigate class-I (HLA-A, -B, -C) and class-II (HLA-DRB1, -DQA1, -DQB1) HLA diversity at the highest, 4-field resolution level in 120 healthy, unrelated, blood donor volunteers. Genomic DNA was extracted and HLA genotypes of class I and DQA1 genes were defined in full-length, -DQB1 from intron 1 to 3′ UTR, and -DRB1 from intron 1 to intron 4 (Illumina MiSeq platform, Omixon Twin algorithms, IMGT/HLA release 3.30.0_5). Linkage disequilibrium statistics, Hardy-Weinberg departures, and haplotype frequencies were inferred by exact tests and iterative Expectation-Maximization algorithm using PyPop 0.7.0 and Arlequin v3.5.2.2 software. Our data provide first description of 4-field allele and haplotype frequencies in Croatian population, revealing 192 class-I and class-II alleles and extended haplotypic combinations not apparent from the existing 2-field HLA reports from Croatia. This established reference database complements current knowledge of HLA diversity and should prove useful in future population studies, transplantation settings, and disease-associated HLA screening.

North African-Mediterranean HLA genetic contribution in a population of the kidney transplant waiting list patients of Canary origin (Gran Canaria)

The peopling of the Canary Islands has been widely debated. The mitochondrial DNA and Y-chromosome data support the idea of a Berber genetic origin coming from the North of Africa (maternal) and a later contribution of the Spanish invaders (paternal). The frequencies of the HLA class II alleles from the Tenerife Island (another Canary Island) have previously been published, postulating a Berber and Atlantic/Iberian contributions to the current population. The HLA class I and class II allele frequencies, haplotype frequencies and phylogenetic comparisons were performed in 215 unrelated individuals from Gran Canaria Island (belonging to the kidney transplant waiting list), with at least three generations of ancestors from Canary Islands, in order to study the different ethnical HLA contributions to the genetic background of the Canary Islanders. Results showed the presence of a compound HLA haplotype of putative Phoenician-Berber origin, A*33:01-C*08:02-B*14:02-DRB1*03:01-DQB1*02:01, likely coming from the combination of haplotypes A*30:02-C*05:01-B*18:01-DRB1*03:01-DQB1*02:01 and A*33:01-C*08:02-B*14:02-DRB1*01:02-DQB1*05:01 of North African (probably Berber) and West Asian Mediterranean (probably Phoenician) origins, respectively. The latter haplotypes and others from the same origin (Berber/Phoenician) are also present in the population studied. Besides, other contributions from the North of Europe, North England-Iberian (Atlantic contribution), and Western Europe/Mediterraneans (Spanish colonization) are also discussed. These data conclude that the current genetic background of the Canary Islands inhabitants has been generated over the years by different ways with an original Phoenician-Berber substrate and several genetic contributions generated in different invasions.

The genetic heterogeneity of Arab populations as inferred from HLA genes

This is the first genetic anthropology study on Arabs in MENA (Middle East and North Africa) region. The present meta-analysis included 100 populations from 36 Arab and non-Arab communities, comprising 16,006 individuals, and evaluates the genetic profile of Arabs using HLA class I (A, B) and class II (DRB1, DQB1) genes. A total of 56 Arab populations comprising 10,283 individuals were selected from several databases, and were compared with 44 Mediterranean, Asian, and sub-Saharan populations. The most frequent alleles in Arabs are A*01, A*02, B*35, B*51, DRB1*03:01, DRB1*07:01, DQB1*02:01, and DQB1*03:01, while DRB1*03:01-DQB1*02:01 and DRB1*07:01-DQB1*02:02 are the most frequent class II haplotypes. Dendrograms, correspondence analyses, genetic distances, and haplotype analysis indicate that Arabs could be stratified into four groups. The first consists of North Africans (Algerians, Tunisians, Moroccans, and Libyans), and the first Arabian Peninsula cluster (Saudis, Kuwaitis, and Yemenis), who appear to be related to Western Mediterraneans, including Iberians; this might be explained for a massive migration into these areas when Sahara underwent a relatively rapid desiccation, starting about 10,000 years BC. The second includes Levantine Arabs (Palestinians, Jordanians, Lebanese, and Syrians), along with Iraqi and Egyptians, who are related to Eastern Mediterraneans. The third comprises Sudanese and Comorians, who tend to cluster with Sub-Saharans. The fourth comprises the second Arabian Peninsula cluster, made up of Omanis, Emiratis, and Bahrainis. It is noteworthy that the two large minorities (Berbers and Kurds) are indigenous (autochthonous), and are not genetically different from "host" and neighboring populations. In conclusion, this study confirmed high genetic heterogeneity among present-day Arabs, and especially those of the Arabian Peninsula.

HLA-A, -B, -C and -DRB1 allele and haplotype frequencies in the Macedonian population based on a family study

AIM

The aim of this study was to determine HLA allele and 2-, 3- and 4-loci haplotype frequencies in a sample from Macedonian population with defined haplotypes based on family history.

MATERIAL AND METHODS

We analysed 286 unrelated individuals with Macedonian origin, parents of patients who needed stem cell transplantation, in the period of 01.01.2003 till 31.12.2016. Allele and haplotype frequencies, as well as Hardy-Weinberg equilibrium were calculated using the Arlequin3.5 software. Population comparison was calculated using the PHYLIP software.

RESULTS

We identified 18 HLA-A, 26 HLA-B, 13 HLA-C and 13 HLA-DRB1 allele group families. The most frequent allele groups in our population were HLA-A*02 (29.0%), HLA-A*24 (13.8%), HLA-B*35 (16.1%), HLA-B*51 (14.7%), HLA-B*18 (14.7%), HLA-C*07 (27.9%), HLA-DRB1*11 (25.5%) and HLA-DRB1*16 (14.8%). The most frequent four loci haplotype was HLA-A*01-B*08-C*07-DRB1*03 (2.7%). Our comparison showed that the Macedonian population is closely related to the neighbouring countries in the Balkan Peninsula.

CONCLUSION

This study provides data about the HLA diversity in the Macedonian population, which can be very important in the process of unrelated donor search, and in addition yields control group for future disease association studies in our population.

High-Resolution HLA-A Typing in Normal Iranian Population

Background:

Human leukocyte antigen (HLA) gene is a highly polymorphic region. HLA typing is required to match patients and donors for transplantation; therefore, development of HLA registries is necessary for finding HLA match donors. HLA system is highly informative, and numerous studies have been conducted on HLA allele distribution in different populations.

Methods:

In this study, 100 unrelated Iranian individuals were typed for HLA-A locus using sequence-based typing method. Samples were subjected to the PCR, followed by Sanger sequencing and software analysis.

Results:

A*02:01 (13%) and A*24:02 (12%) were the two most frequent alleles, while A*01:14, A*02:05, A*02:11, A*02:34, A*02:50, A*11:04, A*23:02, A*24:34, A*25:01, A*26:09, A*26:43, A*29:67, A*30:54, A*31:02, A*31:66, A*32:03, A*32:04, A*33:03, and A*66:15 alleles had the least frequencies (1%).

Conclusion:

This is the first report of HLA-A allele level typing in a randomized population of Iran and can be useful for development of national registries of HLA-typed volunteer marrow donors and local cord blood banks.

A genomic study on distribution of human leukocyte antigen (HLA)-A and HLA-B alleles in Lak population of Iran

Anthropological studies based on the highly polymorphic gene, human leukocyte antigen (HLA), provide useful information for bone marrow donor registry, forensic medicine, disease association studies, as well as infertility treatment, designing peptide vaccines against tumors, and infectious or autoimmune diseases. The aim of this study was to determine HLA-A and HLA-B allele frequencies in 100 unrelated Lak/lᴂk/individuals from Lorestan province of Iran. Finally, we compared the results with that previously described in Iranian population. Commercial HLA-Type kits from BAG (Lich, Germany) company were used for determination of the HLA-A and HLA-B allele frequencies in genomic DNA, based on polymerase chain reaction with sequence specific primer (PCR-SSP) assay. The differences between the populations in distribution of HLA-A and HLA-B alleles were estimated by chi-squared test with Yate's correction. The most frequent HLA-A alleles were *24 (20%), *02 (18%), *03 (12%) and *11 (10%), and the most frequent HLA-B alleles were *35 (24%), *51 (16%), *18 (6%) and *38 (6%) in Lak population. HLA-A*66 (1%), *74(1%) and HLA-B*48 (1%), *55(1%) were the least observed frequencies in Lak population. Our results based on HLA-A and HLA-B allele frequencies showed that Lak population possesses the previously reported general features of Iranians but still with unique.

HLA-A, -B and -DRB1 allele and haplotype frequencies of 8333 Chinese Han from the Zhejiang province, China

The distribution of human leucocyte antigen (HLA) allele and haplotype is varied among different ethnic populations. In this study, HLA-A, -B and -DRB1 allele and haplotype frequencies were determined in 8333 volunteer bone marrow donors of Zhejiang Han population using the polymerase chain reaction sequence-based typing. A total of 52 HLA-A, 96 HLA-B and 61 HLA-DRB1 alleles were found. Of these, the top three frequent alleles in HLA-A, HLA-B and HLA-DRB1 loci, respectively, were A*11:01 (24.53%), A*24:02 (17.35%), A*02:01 (11.58%); B*40:01 (15.67%), B*46:01 (11.87%), B*58:01 (9.05%); DRB1*09:01 (17.54%),DRB1*12:02 (9.64%) and DRB1*08:03 (8.65%). A total of 171 A-B-DRB1 haplotypes with a frequency of >0.1% were presented and the five most common haplotypes were A*33:03-B*58:01- DRB1*03:01, A*02:07-B*46:01-DRB1*09:01, A*30:01-B*13:02-DRB1*07:01, A*33:03-B*58:01-RB1*13:02 and A*11:01-B*15:02-DRB1*12:02. The information will be useful for selecting unrelated bone marrow donors and for anthropology studies and pharmacogenomics analysis.

Identification of cytotoxic T lymphocyte epitopes in dengue virus serotype 1

Dengue virus (DENV) has a serious and growing impact on global health and the exact role of DENV-specific CD8(+) T-cells in DENV infection is still uncertain. In the present study, SYFPEITHI algorithm was used to screen the amino acid sequence of Dengue virus serotype 1 (DENV-1) for potential epitopes, and seven putative HLA-A*1101-restricted and five putative HLA-A*2402-restricted epitopes conserved in hundreds of DENV-1 strains were synthesized. The binding affinity of these epitope candidates to corresponding HLA molecules was evaluated using competitive peptide-binding assay. The immunogenicity and specificity of peptides were further tested in HLA-A*1101 transgenic mice, HLA-A*2402 transgenic mice and peripheral blood mononuclear cells (PBMCs) of patients infected with DENV-1. Percentage inhibition (PI) values calculated in competitive peptide-binding assay showed that six peptides (E39-47 PTLDIELLK, NS5(505-513) GVEGEGLHK, NS2b(15-23) SILLSSLLK, NS5(561-569) ALLATSIFK, NS3(99-107) AVEPGKNPK, and NS4b(159-167) VVYDAKFEK) could bind to HLA-A*1101 molecule with high affinity and five peptides (NS3472-480 QYIYMGQPL, NS4a40-48 AYRHAMEEL, NS5(880-888) DYMTSMKRF, NS3(548-556) SYKVASEGF, and NS3(22-30) IYRILQRGL) have a high affinity for HLA-A*2402 molecule. Enzyme-linked immunospot (ELISPOT) results indicated that these high-affinity peptides were recognized by splenocytes of DENV-1-infected transgenic mice and high-affinity peptide-immunized transgenic mice displayed high levels of peptide-specific IFN-γ-secreting cells. In addition, both peptide-pulsed splenocytes and DENV-1-infected splenic monocytes were efficiently killed by these peptide-specific cytotoxic T lymphocytes. Finally, except NS2b(15-23), 10 high-affinity peptides were recognized by PBMCs of patients infected with DENV-1. These identified epitopes would contribute to the understanding of the function of DENV-specific CD8(+) T-cells.

Polymorphisms of HLA-DRB1, -DQA1 and -DQB1 in inhabitants of Astana, the capital city of Kazakhstan

BACKGROUND

Kazakhstan has been inhabited by different populations, such as the Kazakh, Kyrgyz, Uzbek and others. Here we investigate allelic and haplotypic polymorphisms of human leukocyte antigen (HLA) genes at DRB1, DQA1 and DQB1 loci in the Kazakh ethnic group, and their genetic relationship between world populations.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 157 unrelated Kazakh ethnic individuals from Astana were genotyped using sequence based typing (SBT-Method) for HLA-DRB1, -DQA1 and -DQB1 loci. Allele frequencies, neighbor-joining method, and multidimensional scaling analysis have been obtained for comparison with other world populations. Statistical analyses were performed using Arlequin v3.11. Applying the software PAST v. 2.17 the resulting genetic distance matrix was used for a multidimensional scaling analysis (MDS). Respectively 37, 17 and 19 alleles were observed at HLA-DRB1, -DQA1 and -DQB1 loci. The most frequent alleles were HLA-DRB1*07:01 (13.1%), HLA-DQA1*03:01 (13.1%) and HLA-DQB1*03:01 (17.6%). In the observed group of Kazakhs DRB1*07:01-DQA1*02:01-DQB1*02:01 (8.0%) was the most common three loci haplotype. DRB1*10:01-DQB1*05:01 showed the strongest linkage disequilibrium. The Kazakh population shows genetic kinship with the Kazakhs from China, Uyghurs, Mongolians, Todzhinians, Tuvinians and as well as with other Siberians and Asians.

CONCLUSIONS/SIGNIFICANCE

The HLA-DRB1, -DQA1 and -DQB1 loci are highly polymorphic in the Kazakh population, and this population has the closest relationship with other Asian and Siberian populations.