HLA-A, -B, -C, -DRB1 allele and haplotype frequencies in an African American population

Sequence-based typing was used to identify human leukocyte antigen (HLA)-A, -B, -C, and -DRB1 alleles from 564 consecutively recruited African American volunteers for an unrelated hematopoietic stem cell registry. The number of known alleles identified at each locus was 42 for HLA-A, HLA-B 67, HLA-C 33, and HLA-DRB1 44. Six novel alleles (A*260104, A*7411, Cw*0813, Cw*1608, Cw*1704, and DRB1*130502) not observed in the initial sequence-specific oligonucleotide probe testing were characterized. The action of balancing selection, shaping more 'even' than expected allele frequency distributions, was inferred for all four loci and significantly so for the HLA-A and DRB1 loci. Two-, three-, and four-locus haplotypes were estimated using the expectation maximization algorithm. Comparisons with other populations from Africa and Europe suggest that the degree of European admixture in the African American population described here is lower than that in other African American populations previously reported, although HLA-A:B haplotype frequencies similar to those in previous studies of African American individuals were also noted.     

HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies in the Serbian population

This study provides the first published detailed analysis of five loci polymorphisms as well as reports of two, three and five loci haplotype frequencies in the Serbian population in a sample of 1992 volunteer bone marrow donors recruited from different part of the country. Typing was performed by PCR SSO method combined with PCR SSP techniques to resolve ambiguities. In total, 16 HLA-A, 28 HLA-B, 14 HLA-C, 13 HLA-DRB1 and 5 HLA-DQB1 allelic groups were identified. The most frequent in allele groups are HLA-A^∗02 (29.5%), HLA-A^∗01 (14.2%), HLA-B^∗35 (13.1%), HLA-B^∗51 (12.8%), HLA-C^∗07 (24.8%), HLA-DRB1^∗11 (16.9%), HLA-DRB1^∗13 (13.2%), HLA-DQB1^∗03 (33.3%) and DQB1^∗05 (33.0%). The most frequent three- and five-loci haplotypes were A^∗01-B^∗08-DRB1^∗03 (5.9%) and A^∗02-B^∗18-DRB1^∗11 (1.9%), A^∗01-B^∗08-C^∗07-DRB1^∗03-DQB1^∗02 (6.6%) followed by A^∗02-B^∗18-C^∗07-DRB1^∗11-DQB1^∗03 (2.5%), then A^∗33-B^∗14-C^∗08-DRB1^∗01-DQB1^∗05 and A^∗02-B^∗35-C^∗04-DRB1^∗16-DQB1^∗05 (2.2% both), respectively. The results of cluster analysis showed that the Serbian population is closely related to the populations living in central Balkan and neighboring European regions. The level of allelic diversity found in this study are relevant to facilitate searching for unrelated matched donor and provide a healthy control population from our region that should be useful in the future disease association study.     

HLA-A, -B, and -DRB1 polymorphism defined by sequence-based typing of the Han population in Northern China

DNA typing for human leukocyte antigen (HLA)-A, -B and -DRB1 was performed using polymerase chain reaction-sequence-based typing method on 618 randomly selected healthy individuals of the Han population in Northern China. Allele frequencies and haplotypes were statistically analyzed. A total of 84 HLA-A alleles, 143 B alleles, and 122 DRB1 alleles were detected, and 853 A-B-DRB1 haplotypes, 473 A-B haplotypes, and 551 B-DRB1 haplotypes were statistically inferred. Statistical analysis of three-locus haplotypes showed that A*0207-B*4601-DRB1*0901 (3.06%) was the most predominant. Gene frequencies and haplotypic associations within HLA-A, -B, and -DRB1 loci were determined at a high-resolution (four digit) allelic level and should provide useful information in anthropology, bone marrow donor registry, legal medicine, and disease association studies.     

HLA-A, -B and -DRB1 allele frequencies in the Bangladeshi population

Population genetic studies have become an invaluable tool because of the extreme polymorphism found at some of the loci of the human leukocyte antigen (HLA) system. In this study, we are reporting for the first time the genetic polymorphism of 141 healthy unrelated Bangladeshi Bangalees living in central region of Dhaka. We studied the HLA-A, -B and -DRB1 loci using polymerase chain reaction with sequence-specific primers. The allelic frequencies, two and three locus haplotype frequencies were statistically analyzed. A total of 16 HLA-A alleles, 26 HLA-B alleles and 14 HLA-DRB1 alleles were detected. A*33-B*44 (8.15%) was the most common two loci class 1 haplotype, whereas A*33-B*44-DRB1*07 (6.38%) was the most frequent three loci haplotype. The most common HLA-A, HLA-B and HLA-DRB1 alleles were A*33 (17.02%), B*15 (19.5%) and DRB1*15 (29.07%), respectively. Construction of phylogenetic tree using average linkage between groups and correspondence analysis showed close associations with Indian non-tribal random Dravidians, north Indian Hindus and some relations with Mongolian and Pakistani populations. We believe this data will provide useful information for bone marrow registry, legal medicine, disease association and anthropological studies.     

Allele and extended haplotype polymorphism of HLA-A, -C, -B, -DRB1 and -DQB1 loci in Polish population and genetic affinities to other populations

Human leukocyte antigen (HLA)-A, -C, -B, -DRB1 and -DQB1 alleles were typed in 200 Polish healthy volunteers recruited for stem cell donor registry, using sequence-specific primer (SSP) and direct sequencing-based methods. Enhanced Bayesian approach of expectation maximization algorithm provided by phase platform was used for extended HLA haplotype inferences. The numbers of identified alleles (four-digit resolution) were 23, 23, 44, 27 and 18 alleles in HLA-A, -C, -B, -DRB1 and -DQB1 loci, respectively, of both northern and southern European frequency characteristics. The most frequent extended haplotypes were Cw*0701-B*0801-DRB1*0301-DQB1*0201 and Cw*0702-B*0702-DRB1*1501-DQB1*0602, found in 25 and 23 copies, respectively, in 400 tested chromosomes. The extended haplotype found in the Polish population with higher frequency than in other European population was A*2501-Cw*1203-B*1801-DRB1*1501-DQB1*0602 (six copies) and especially its class I fragment (14 copies). The neighbour-joining and correspondence analyses showed Central and northern European genetic affinities of Polish population. In most cases, the observed European allele and haplotype gradients display smooth topography around Polish population. Poles along with Western Slavs have their specific contribution in the demographic history of Europe. Our results will intensify the use of population data in stem cell donor search and can potentially improve current algorithms, facilitating selection of acceptable donors for patients in need of stem cell transplant.     

HLA-A, -B, -DRB1, -DQA1, and -DQB1 polymorphism in thais

In this study we examined HLA-A, -B, -DRB1, -DQA1, and -DQB1 gene, allele, and haplotype frequencies in two ethnic Thai populations. We compared these frequencies to the known HLA class I and II allele profiles of non-Thai mainland and insular Southeast (SE) Asians. HLA-A locus gene and allele frequencies, are comparatively homogeneous in both Thai and non-Thai SE Asians. In contrast, HLA-B, -DRB1, -DQA1, and -DQB1 gene and allele frequencies, show more ethnic and geographic variation in SE Asians. Conserved haplotypes, or combinations of linked HLA class I and II alleles were detected in Thais, but at relatively low frequencies. It would appear that ethnic Thais, reflect an admixture of peoples from both the northern mainland and southern island groups of SE Asia.     

大连地区汉族人群HLA-A,-B,-DRB1 位点基因多态性研究

目的:了解大连地区汉族人群HLA-A,-B,-DRB1 位点基因多态性分布特征。方法:采用基因测序及序列特异性寡核苷酸探针的方法对10 000 名居住在大连地区健康汉族造血干细胞捐献者进行HLA-A,-B,-DRB1 基因分型,从而得到等位基因频率。利用ARLEQUIN 软件估算单倍型频率及连锁不平衡参数,使用poptree2 软件计算两人群间遗传距离(DA)。结果:大连地区汉族人群中共检出HLA-A 基因18 个、HLA-B 基因32 个、HLA-DRB1 基因13 个,HLA-A*02(31.65%)、B*40(14.84%)、DRB1*15(15.82%)最为常见。三位点单倍型中A*30-B*13-DRB1*07(4.56%)频率最占优势,A*02-B*46-DRB1*09(2.43%)次之。A*30-B*13(6.00%)与B*13-DRB1*07(59.89%)为频率最高的两位点单倍型。A*33-B*58与B*13-DRB1*07 为大连地区汉族人群中最强连锁不平衡两位点单倍型,连锁不平衡参数分别为0.336 6 和0.665 1。大连汉族人群与国内某些人群进行比较,遗传距离最近的是黑龙江(0.001),其次为吉林(0.002)和山东(0.002),遗传距离最远的是台湾(0.047)。与国外其他人群进行比较,遗传距离最近的是泰国(0.029)和韩国(0.03),而遗传距离最远的是意大利(0.183)。结论:大连地区汉族人群HLA-A,-B,-DRB1 基因具有较为丰富的多态性,其分布符合北方人群的特点。     

湖北土家族人群HLA-A、B等位基因及单倍型多态性的分布

目的研究湖北五峰县土家族190名无亲缘关系健康个体HLA-A、B等位基因及单倍型频率的分布，为进一步研究HLA基因多态性与疾病的关联奠定基础。方法采用序列分型（sequence-baaed typing，SBT）法对最具多态性的HIA-A、B基因2、3外显子进行了基因型分析，采用Arlequin软件对群体基因、单倍型频率进行最大估计值的计算。结果HLA-A、B等位基因符合Hardy-Weinberg平衡定律（P〉0．05），无显著的连锁不平衡现象，共检测出26个HLA-A等位基因及41个HLA-B等位基因，其中频率最高的为A＊0201（0．16053），A＊110101（0．14737），A＊24020101（0．14211），B＊4001（0．14737），B＊4601（0．13947），其次为A＊0207（0．08947），A＊0206（0．08158），B＊1301（0．07632），B＊5801（0．08947），B＊1501（0．09737），而大于0．05％的为A＊330301（0．05526），B＊1502（0．05526），B＊3501（0．05263），单倍型分布较普遍的为A＊0202-B＊4001（0．04196），A＊0201-B＊4601（0．03625）。结论采用高分辨测序分型法对土家族人群HLA-A、B等位基因进行分型的实验结果可做为湖北土家族人HLA-A、B等位基因、单倍型频率的群体资料，对进一步开展群体遗传学、临床器官移植、疾病关联、HLA遗传学特征、法医学、人类学等研究具有重要意义。     

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.

HLA-A, -B, -C,and -DRB1 genotyping and haplotype frequencies for a Hong Kong Chinese population of 7595 individuals

HLA-A, -B, -C and -DRB1 gene and haplotype frequencies have been calculated from 7595 southern Chinese unrelated donors in a Hong Kong Bone Marrow Donor Registry. This is the first large-scale paper to report the distribution of A-C-B-DRB1 alleles in Hong Kong Chinese. This information is important for phylogenetic, comparative studies and estimating the optimal and cost-effective donor size and likelihood of obtaining appropriately matched donors for Chinese patients awaiting haematopoietic stem cell transplantation. The allele and haplotype data are available in the Allele Frequencies Net Database under the population name ‘‘Hong Kong Chinese BMDR’’ and the identifier (AFND003357).     

Allelic and haplotypic diversity of HLA-A, -B, -C, -DRB1, and -DQB1 genes in the Korean population

High-resolution human leukocyte antigen (HLA) typing exposes the unique patterns of HLA allele and haplotype frequencies in each population. In this study, HLA-A, -B, -C, -DRB1, and -DQB1 genotypes were analyzed in 485 apparently unrelated healthy Korean individuals. A total of 20 HLA-A, 43 HLA-B, 21 HLA-C, 31 HLA-DRB1, and 14 HLA-DQB1 alleles were identified. Eleven alleles (A*0201, A*1101, A*2402, A*3303, B*1501, Cw*0102, Cw*0302, Cw*0303, DQB1*0301, DQB1*0302, and DQB1*0303) were found in more than 10% of the population. In each serologic group, a maximum of three alleles were found with several exceptions (A2, B62, DR4, DR14, and DQ6). In each serologic group exhibiting multiple alleles, two major alleles were present at 62-96% (i.e. A*0201 and A*0206 comprise 85% of A2-positive alleles). Multiple-locus haplotypes estimated by the maximum likelihood method revealed 51 A-C, 43 C-B, 52 B-DRB1, 34 DRB1-DQB1, 48 A-C-B, 42 C-B-DRB1, 46 B-DRB1-DQB1, and 30 A-C-B-DRB1-DQB1 haplotypes with frequencies of more than 0.5%. In spite of their high polymorphism in B and DRB1, identification of relatively small numbers of two-locus (B-C and DRB1-DQB1) haplotypes suggested strong associations of those two loci, respectively. Five-locus haplotypes defined by high-resolution DNA typing correlated well with previously identified serology-based haplotypes in the population. The five most frequent haplotypes were: A*3303-Cw*1403-B*4403-DRB1*1302-DQB1*0604 (4.2%), A*3303-Cw*0701/6-B*4403-DRB1*0701-DQB1*0201/2 (3.0%), A*3303-Cw*0302-B*5801-DRB1*1302-DQB1*0609 (3.0%), A*2402-Cw*0702-B*0702-DRB1*0101-DQB1*0501 (2.9%), and A*3001-Cw*0602-B*1302-DRB1*0701-DQB1*0201/2 (2.7%). Several sets of allele level haplotypes that could not be discriminated by routine HLA-A, -B, and -DRB1 low-resolution typing originated from allelic diversity of A2, B61, DR4, and DR8 serologic groups. Information obtained in this study will be useful for medical and forensic applications as well as in anthropology.     

Genetic polymorphisms at HLA-A, -B, and -DRB1 loci in Han population of Xi'an city in China

Aim

To determine genetic polymorphisms at human leukocyte antigen (HLA)-A, -B, and -DRB1 loci in Han population of Xi’an city in China.

Methods

Polymerase chain reaction-based reverse line-strip sequence specific oligonucleotide hybridization was used to determine the alleles of HLA-A, -B, and -DRB1 in 516 unrelated, healthy individuals of Han population in Xi’an. Allele frequencies at HLA-A, -B, and -DRB1 loci were estimated by direct counting method. Haplotype frequencies were calculated from genotype data by expectation maximization.

Results

A total of 14 alleles of HLA-A, 33 alleles of HLA-B, and 13 alleles of HLA-DRB1 were found. The most common alleles were HLA-A*02 (28.39%), A*11 (19.19%), and A*24 (16.28%); HLA-B*13 (11.05%), B*15 (B62: 9.30%), and B*51 (8.53%); and HLA-DRB1*15 (17.15%), DRB1*09 (13.18%), and DRB1*04 (10.85%). The most common haplotypes of HLA-A-B-DRB1 haplotype were HLA-A*30-B*13-DRB1*07 (3.93%), HLA-A*02-B*46-DRB1*09 (3.20%), and HLA-A*33-B*58-DRB1*17 (1.63%).

Conclusion

The finding that the HLA loci are highly polymorphic in Han population of Xi’an City may be useful for population genetics, HLA-related studies, human identification, and paternity tests in forensic sciences.Human leukocyte antigen (HLA) is a large, closely linked cluster of genes located on chromosome 6p21.3 (1). The HLA system is one of the most polymorphic immunological genetic systems in human genome and usually used in the anthropological analysis, disease linkage analysis, population genetics, forensic sciences, and organ transplantation, especially bone marrow transplantation (2,3). Previous studies have shown that allele and haplotype distribution in the HLA system differ from one ethnic group to another or between the members of the same ethnic group living in different geographic areas. Also, certain alleles are exclusively found in some ethnic groups (4). The comparisons between different populations using genetic distances calculated from HLA allele or haplotype frequencies have been used to determine the genetic relationship between different ethnic groups, so the HLA genetic markers are valuable tools for tracing ancient human migrations and determining the origins of different ethnic groups (5-8). In the present study, we determined the genetic polymorphisms at HLA-A, -B, and -DRB1 loci in a Chinese Han population in Xi’an city and compared them with other neighboring populations.     

HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies in a population of 432 healthy unrelated individuals from Albania

This paper reports the HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype polymorphism in a population of 432 healthy individuals from Albania. First-field HLA genotyping was performed by polymerase chain reaction sequence-specific priming and/or oligonucleotide methods. The data were analyzed statistically using gene counting and Arlequin software packages. No deviation from Hardy Weinberg Equilibrium was detected at any of the loci studied. The HLA genotypic data of the population sample reported here are available publicly in the Allele Frequencies Net Database and they can serve as a reference database for further HLA-based population genetics studies including the Albanian population.     

HLA-A, -B,and -DRB1 allele and haplotype diversity in a cohort of Brazilian renal transplant candidates

The distribution of organs for renal transplant depends on HLA matching between donor and recipient. This study aimed to characterize the allele and haplotype frequencies of HLA-A, -B, and -DRB1 in a cohort of renal transplant candidates populations in the region of Sao José do Rio Preto (State of São Paulo), to compare the allele frequencies between Caucasian and Black in that region, as well as to compare these frequencies with different Brazilian populations reported. The HLA-A, -B, and -DRB1 allele and haplotypes frequencies were analyzed in a sample of 2.624 individuals and classified according to the ethnic group (2.347 Caucasians and 277 Blacks). The HLA class I (A, B) and class II (DRB1) specificities were determined by complement-dependent microlymphocytotoxic (CDC) and Polymerase Chain Reaction/Sequence Specific Priming (PCR-SSP) methods, respectively. Twenty-one HLA-A, 34 HLA-B and 13 HLA-DRB1 allelic groups were identified. The most frequent alleles for each locus were HLA-A¹02, HLA-B¹35, and HLA-DRB1¹11. The most frequent haplotypes found were A¹01 B¹08 DRB1¹03 among Caucasians and A¹29 B¹15 DRB1¹04 among Blacks. The most common alleles for each locus among RTx were HLA-A¹02, HLA-B¹35 and HLA-DRB1¹11. The haplotypes A¹01 B¹08 DRB1¹03 and A¹29 B¹44 DRB1¹07 prevailed among Caucasians and Blacks, respectively. This study provides the first data on the HLA-A, HLA-B and HLA-DRB1 allele and haplotype frequencies of renal transplant candidates populations in the region of Sao José do Rio Preto.     

HLA-A, -B, -DRB1 allele and haplotype frequencies of 920 cord blood units from Central Chile

We present human leukocyte antigen (HLA) haplotype and allele/antigenic group frequencies derived from a data set of 920 umbilical cord blood units collected in Central Chile. HLA-A and -B genotypes were typed using sequence specific oligonucleotide probe methods while HLA-DRB1 genotypes were obtained from sequencing-based typing. The most frequent haplotype is A*29~B*44~DRB1*07:01 with an estimated frequency of 2.1%.     

HLA-A, -B, -C, and -DRB1 allele and haplotype frequencies distinguish Eastern European Americans from the general European American population

Sequence-based typing was used to identify human leukocyte antigen (HLA)-A, -B, -C, and -DRB1 alleles from 558 consecutively recruited US volunteers with Eastern European ancestry for an unrelated hematopoietic stem cell registry. Four of 31 HLA-A alleles, 29 HLA-C alleles, 59 HLA-B alleles, and 42 HLA-DRB1 alleles identified (A*0325, B*440204, Cw*0332, and *0732N) are novel. The HLA-A*02010101g allele was observed at a frequency of 0.28. Two-, three-, and four-locus haplotypes were estimated using the expectation-maximization algorithm. The highest frequency extended haplotypes (A*010101g–Cw*070101g–B*0801g–DRB1*0301 and A*03010101g–Cw*0702–B*0702–DRB1*1501) were observed at frequencies of 0.04 and 0.03, respectively. Linkage disequilibrium values (     ) of the constituent two-locus haplotypes were highly significant for both extended haplotypes ( P values were less than 8 × 10⁻¹⁰) but were consistently higher for the more frequent haplotype. Balancing selection was inferred to be acting on all the four loci, with the strongest evidence of balancing selection observed for the HLA-C locus. Comparisons of the A–C–B haplotypes and DRB1 frequencies in this population with those for African, European, and western Asian populations showed high degrees of identity with Czech, Polish, and Slovenian populations and significant differences from the general European American population.