山东省烟台和威海地区汉族HLA-A、B和DRB1等位基因多态性及遗传距离分析

目的 分析山东省烟台和威海地区汉族人群人类白细胞抗原(human leukocyte antigen,HLA)-A、B、DRB1等位基因的多态性分布特征,并探讨该人群与其他人群的亲缘关系.方法 应用聚合酶链反应-序列特异性寡核苷酸探针方法(polymerase chain reaction-sequence specific olignucleotide probe,PCR-SSOP)对山东省烟台和威海地区4062名无亲缘关系的汉族健康个体进行HLA-A、B、DRB1基因分型.采用Arlequin3.5软件计算HLA等位基因频率、单倍型频率和连锁不平衡参数,按内氏公式计算出不同人群之间的遗传距离,并利用Mega5.0软件构建系统发生树.结果 该人群HLA-A、B、DRB1等位基因分布均符合Hardy-Weinberg平衡(P＞0.1).3个基因座分别检出18、33和13个等位基因,其中等位基因频率分布最高的分别是A* 02 (0.2935)、B* 15 (0.1485)和DRB1* 15 (0.1621);最常见的单倍型为A* 30-B* 13-DRB1* 07(0.0649),A* 33-B* 58、A*66-DRB1* 13、B*08-DRB1* 03呈现最强的连锁不平衡;山东省烟台和威海汉族人群与吉林省汉族人群遗传距离最小,为0.0034.结论 山东省烟台和威海地区汉族人群HLA-A、B、DRB1等位基因和单倍型具有较高的遗传多态性,该人群与吉林汉族人群亲缘关系最近.     

广西汉族人群HLA-A、-B、-DRB1高分辨等位基因和单倍型多态性的初步分析

目的分析广西汉族人群人类白细胞抗原(human leukocyte antigen,HLA)-A、-B、-DRB1等位基因和单倍型的分布特征。方法采用多聚酶链式反应-基于测序的分型技术(polymerase chain reaction-sequence based typing,PCR-SBT)对广西地区1 644名汉族无关个体进行HLA-A、-B、-DRB1等位基因和单倍型多态性的分型,使用Arlequin软件(3.5.2.2)计算HLA等位基因频率、单倍型频率和连锁不平衡参数。使用MEGA v6.0软件构建系统发生树,并与其他部分中国汉族人群的基因频率进行比较。结果该人群HLA-A、-B、-DRB1等位基因分布均偏离Hardy-Weinberg平衡(P0.05),3个位点分别检出37种HLA-A,70种HLA-B和37种HLA-DRB1等位基因。其中,等位基因频率分布最高的分别是A~*11∶01(28.86%)、B~*46∶01(14.26%)和DRB1~*15∶01(13.32%),最常见的单倍型是A~*33:03-B~*58∶01-DRB1~*03∶01(6.12%),A~*02∶07-B~*46∶01、A~*11∶01-DRB1~*15∶01和B~*58∶01-DRB1~*03∶01呈现最强的连锁不平衡。该人群与广西壮族人群亲缘关系最近,其多态性最接近的汉族是中国南方汉族。结论广西汉族人群HLA-A、-B、-DRB1等位基因和单倍型有较高的遗传多态性,将为中国人群在临床寻找HLA匹配的无关亲缘供者、法医学研究以及人类学研究等提供有价值的遗传学依据。     

济南汉族人群HLA-A、B、DRB1等位基因高分辨多态性分析

目的 分析济南地区汉族人群人类白细胞抗原(human leukocyte antigens,HLA)-A、B、DRB1座位等位基因的高分辨多态性.方法 采用PCR-测序分型(PCR-sequence-based typing,PCR-SBT)对鲁南地区483名无血缘关系的汉族健康个体进行HLA-A、B、DRB1座位高分辨基因分型,采用Arlequin3.5软件计算等位基因频率、单倍型频率,并就常见等位基因与其他人群进行比较.结果 济南汉族HLA-A、B、DRB1座位分别检出27、56和41个等位基因,其中等位基因频率分布最高的分别是A* 11∶01 (0.1615)、B*13∶02(0.1163)和DRB1* 07∶01 (0.1763);最常见的A*-B*-DRB1*单倍型是A*30∶01-B* 13∶02-DRB1* 07∶01 (0.0867).结论 济南地区汉族人群HLA-A、B、DRB1等位基因和单倍型具有较高的多态性.     

浙江汉族人群HLA-A、-B、-DRB1高分辨等位基因频率和单体型分析

研究表明HLA具有高度连锁不平衡的遗传特点,不同民族或地区人群基因或单体型频率分布存在明显的不同,可作为不同种群特征性的遗传标志,目前有关不同人群HLA-A、-B、-DRB1基因频率和单体型分布情况已有众多的报道,但大多研究采用低分辨基因分型方法[1-3].本实验采用高分辨基因分型技术检测了1100例浙江汉族人群的HLA-A、-B、-DRB1位点,分析了人群HLA高分辨等位基因分布、单体型频率及连锁不平衡特征,现将结果报告如下.     

西北地区汉族人群HLA-A、-B、-DRB1基因座单倍型分析

目的 分析西北地区汉族群体HLA-A、-B和-DRB1基因座等位基因频率和HIA-A-B、B-DRB1和A-B-DRB1单倍型，获得单倍型频率数据。方法 采用序列特异性寡核苷酸探针反向斑点杂交技术对西北地区62个家系和101个无关个体HLA-A、-B和-DRB1基因座进行基因分型，分析HLA单倍型。结果 在西北地区汉族人群中检出15个HLA-A等位基因，28个HLA-B等位基因，13个HLA-DRB1等位基因，A02、A11、A24、B13、B15、1340、DRB1＊04、DRB1＊07、DRB1＊09和DRB1＊15基因频率较高（〉10％），A02（0．3244）、B13（0．1200）和DRB1＊15（0．1400）等位基因频率最高。分析得出HLA-A-B、B-DRB1、A-B-DRB1单倍型分别有122、147和278种，83种A-B-DRB1单倍型有至少两条以上相同的单倍型，占总单倍型数的18．44％（83／450）。A30-B13-DRB1＊07、A02-B46-DRB1＊09、A01-B37-DRB1＊10、A24-B15-DRB＊15、A02-B46-DRB1＊08、A33-B58-DRB1＊03是最常见的单倍型。结论 西北地区汉族群体HLA单倍型多态性较为丰富，等位基因频率和单倍型频率数据可用于骨髓移植供者的选择、法医学亲权鉴定以及人类学研究。     

造血干细胞移植56例人类白细胞抗原基因和单倍型分析

背景：收集56例欲行造血干细胞移植的供受者,均为无血缘关系的江西省汉族人群。了解个体的人类白细胞抗原基因型和单倍型。 目的：分析56例造血干细胞移植供受者的人类白细胞抗原基因频率,单倍型频率。 方法：收集56例欲行造血干细胞移植的供受者,均无血缘关系的江西省汉族人群。应用PCR-SSP的方法进行人类白细胞抗原(HLA)-A、B、DRB1基因分型,计算出HLA-A、B、DRB1各位点的基因频率和单倍型频率。 结果与结论：56例供受者测出HLA-A位点等位基因8种,HLA-B位点等位基因19种,HLA-DRB1位点等位基因13种,呈现出丰富的基因多态性。56例供受者两位点共224条等位基因中,A﹡02-B﹡46、A﹡11-B﹡40、B﹡46-DRB1﹡09单倍型的频率高于0.10。有10种A-B单倍型,4种B-DRB1单倍型呈现出显著的连锁不平衡。提示江西省汉族人群人类白细胞抗原基因具有较丰富的基因多态性。     

山东地区汉族人群中HLA-A、-B、-DRB1等位基因与原因不明卵巢早衰相关性研究

目的探讨HLA-A,-B和-DRB1位点等位基因多态性与原因不明卵巢早衰(premature ovarian failure,POF)的相关性。方法利用毛细管电泳测序技术(Capillary Electrophoresis),对36例汉族原因不明POF患者进行HLA-A,-B,-DRB1基因分型,并以865例山东健康汉族个体造血干细胞分型资料作为对照,分析HLA等位基因频率在两组中的分布差异。结果 POF组中HLA-A*33、HLA-B*07、HLA-B*52和HLA-B*55等位基因频率显著高于对照组(P<0.05)。HLA-A*33的等位基因频率POF组为19.44%,而正常对照组为10.17%,RR=2.18;HLA-B*07的等位基因频率POF组为12.50%,而正常对照组为5.32%,RR=2.65;HLA-B*52的等位基因频率POF组为11.11%,而正常对照组为4.10%,RR=3.06;HLA-B*55的等位基因频率POF组为5.56%,而正常对照组为1.50%,RR=4.23。结论山东汉族人群中HLA-A*33、HLA-B*07、HLA-B*52和HLA-B*55等位基因可能是POF的易感基因。     

应用SBT直接测序分型法研究中国南方汉族人群HLA五个基因座单倍型

目的 研究中国南方汉族人群HLA-A、B、Cw、DRBl、DQBl等位基因多态性及单倍型的分布特征.方法 应用聚合酶链反应-直接测序分型(polymerase chain reaction sequence-based typing,PCR-SBT)法对186名中国南方汉族健康人群HLA-A、B、Cw、DRBl、DQBl进行基因分型.结果 检出的HLA-A、B、Cw、DRBl、DQBl等位基因分别有28、49、24、29、20种.经统计分析A*0207-B*4601(10.81%),A*3303-B*5801(6.14%),B*4601-DRBl*0901(6.22%),B*4001*DRBl*0901(3.78%),DRBl*0901-DQBl*0303(12.16%)和DRBl*1202-DQBl*0301(8.38%)单倍型呈强连锁不平衡单倍型(RLF≥0.5,X<'2>>3.84,P<0.05);A*0207-B*4601-Cw*0102(10.75%),A*3303-B*5801-Cw*0302(5.14%),A*0207-B*4601-DR*0901(5.07%),A*3303-B*5801-DRBl*0301(2.96%),A*0207-B*4601-Cw*0102-DRBl*0901-DQBl*0303(4.87%)和A*1101-B*1301-Cw*0304-DRBl*1501-DQBl*0601(2.43%)单倍型分别是中国南方汉族人群常见单倍型.结论 中国南方汉族人群HLA 5个基因座单倍型分布具有高度的遗传多态性且有其自身分布特点.本研究获得的较完整的HLA 5个基因座单倍型分布数据,将为人类学、HLA疾病相关性和器官移植等研究提供遗传学参考数据.     

我国部分省份(地区)汉族人群HLA-Ⅰ类基因多态性地区差异分析

目的 探讨我国部分省份(地区)汉族人群HLA-Ⅰ类经典基冈座位HLA-A、HLA-B、HLA-Cw位点的群体遗传学特点及其基因频率分布的地区差异.方法 选取1014例无关汉族拟行造血干细胞移植治疗患者及其健康家系供者的血液样本,提取基因组.DNA后,采用序列特异性引物聚合酶链式反应(PCR-SSP)分型技术进行HLA-A、HLA-B、HLA-Cw位点基因分型,分析不同地区汉族人群及不同种族间的基因频率分布特征.基于文献报道的我国不同地区汉族人群及不同种族的HLA-Ⅰ类基因频率资料,计算种群间遗传距离(D),比较不同地区汉族人群及不同种族间遗传距离差异.结果 Hard-Weinberg吻合度检验表明,本研究抽样群体适于进行遗传学统计分析.HLA-A位点共检测出14种基因型,最常见的是A*02(0.330)、A*11(0.240)、A*24(0.155)、A*33(0.075);HLA-B位点共检测出27种基因型,最常见的是B*13(0.134)、B*15(0.143)、B*40(0.133)、B*46(0.102);HLA-Cw位点共检测出13种基因型,最常见的是Cw*01(0.157)、Cw*03(0.247)、Cw*07(0.181)、Cw*08(0.106).群体汉族与其他人种间HLA-A、HLA-B基因频率差异均有统计学意义(P<0.05);除兰州汉族人群仅同南方汉族、湖南、山东、江苏、台湾汉族人群间HLA-A、HLA-B基因频率差异有统计学意义(P<0.05)外,其余各地区汉族人群间HLA-A、HLA-B基因频率差异均有统计学意义(P<0.05).各地区汉族人群间平均遗传距离D=0.164,辽宁和北方汉族人群间遗传距离(D=0.064)最小,江苏与湖南汉族人群间遗传距离(D=0.299)最大;不同地区汉族人群间遗传距离普遍小于种族间遗传距离.结论 我国不同地区汉族人群HLA-Ⅰ类基因频率分布存在显著差异,但其差异要明显小于世界不同人种间的分布差异.我国汉族人群所特有的HLA-Ⅰ类基因频率分布格局资料对区域性疾病的个性化治疗、遗传易感性及疾病防治等研究具有很好的理论及应用价值.     

人类白细胞抗原HLA-B/DR座位间基因重组一家系

目的 了解一家系人类白细胞抗原(human leucocyte antigen,HLA)复合体HLA-B/DR座位间的基因重组.方法 采集拟进行造血干细胞移植的1例急性淋巴细胞白血病患者(男,16岁)及其父母和3个姐姐的外周血标本,首先对其HLA Ⅰ、Ⅱ类A、B、DRB13个位点采用聚合酶链反应-序列特异寡核苷酸探针技术(polymerase chain reaction-sequence specific oligonucleotide,PCR-SSO)和聚合酶链反应-序列特异性引物技术(polymerase chain reaction sequence specific primer,PCR-SSP)进行低分辨基因分型,然后用基于测序的分型方法(sequencing-based typing,SBT)进行高分辨基因分型,再进行遗传家系分析研究,确定HLA基因重组相关位点.结果 HLA高分辨基因分型的结果证实患者的2条单倍型分别为A*3101-B*1301-DRB1*0701和A*3303-B*4403-DRB1*1302;其父亲的2条单倍型为A*3001-B*1302-DRB1*0701和A*3101-B*1301-DRB1*1501.从遗传家系分析显示,患者所携有的父源A*3101-B*1301单倍体是源自父亲的1条染色单体,而DRB1*0701则源自父亲的另1条染色单体,这表明父亲的2条染色单体在减数分裂时HLA-B和-DRB1基因座位间发生了交换,重组后的单倍型又完整地遗传给了患者.结论 发现了1个中国汉族人群HLA-B/DR基因座位间的基因重组家系.     

Distribution of human leucocyte antigen-A, -B and -DR alleles and haplotypes at high resolution in the population from Jiangsu province of China

The frequencies of human leucocyte antigen (HLA)-A, -B and -DRB1 alleles and haplotypes were statistically analysed among 3238 donors from Chinese Marrow Donor Program (CMDP) Jiangsu Branch. All donors were typed using polymerase chain reaction-sequence-based typing (PCR-SBT) method or polymerase chain reaction-reverse sequence-specific oligonucleotide probe (PCR-rSSOP) method. As a result, a total of 46 A, 85 B and 51 DRB1 alleles were found in Jiangsu population. The first three frequent alleles in HLA-A, -B and -DRB1 loci respectively were A*11:01(16.52%), A*24:02(15.10%) and A*02:01(13.02%); B*13:02(11.60%), B*46:01(8.89%) and B*58:01(7.12%); and DRB1*07:01(15.78%), DRB1*09:01(15.26%) and DRB1*15:01(9.76%). The top two frequent A-B-DRB1 haplotypes were A*30:01-B*13:02-DRB1*07:01(8.87%) and A*02:07-B*46:01-DRB1*09:01(2.79%); the top three A-B haplotypes were A*33:03-B*58:01-DRB1*03:01(2.59%), A*30:01-B*13:02(9.92%) and A*33:03-B*58:01(5.48%); the top two B-DRB1 haplotypes were B*13:02-DRB1*07:01(10.23%) and B*46:01-DRB1*09:01(4.61%); the top two A-DRB1 haplotypes were A*30:01-DRB1*07:01(8.96%) and A*33:03-DRB1*13:02(3.95%). These findings provided useful information in the study of genetics and anthropology in Chinese Han population. It also served as a basic guide for selection of future donors in CMDP Jiangsu Branch.     

Distribution of human leukocyte antigen alleles and haplotypes in Oroqen and Ewenki nationality minority in Inner Mongolia Autonomous Region of China

The frequencies of the human leukocyte antigen alleles HLA-A,-B, DRB1 and the A-B, A-DRB1, B-DRB1, A-B-DRB1 haplotypes were investigated through means of PCR-based reverse line-strip sequence specific oligonucleotide hybridization on 108 Oroqen and 104 Ewenki nationality unrelated healthy individuals from the Inner Mongolia Autonomous Region of China. A total of thirteen different HLA-A alleles, 21 different HLA-B alleles and 13 different HLA-DRB1 alleles were detected in the Oroqen ethnic group and the most frequent HLA alleles found were A*24(35.65%), B*15(17.92%), and DRB1*09(17.59%), respectively. The common HLA-A-B-DRB1 haplotypes were A*24-B*40-DRB1*09(5.09%), A*24-B*48-DRB1*12(2.78%) and A*24-B*51-DRB1*04(2.78%); and the HLA-A*33-B*58, A*30-B*13, A*01-B*37, A*33-DRB1*03, A*01-DRB1*10, A*30-DRB1*07, B*37-DRB1*10, B*58-DRB1*03, B*38-DRB1*08, B*13-DRB1*07 were significant positive linkage disequilibrium in the Oroqen nationality group. In total, 14 different HLA-A alleles, 27 B alleles and 12 DRB1 alleles were found in Ewenki nationality group, and the most frequent HLA alleles found were A*24(24.49%), B*40(17.35%), and DRB1*04(14.80%), respectively. The common HLA-A-B-DRB1 haplotypes were A*33-B*58-DRB1*03(6.25%), A*01-B*51-DRB1*11(2.88%) and A*24-B*40-DRB1*09(2.88%); the HLA-A*33-B*58, A*29-B*44, A*03-B*52, A*33-DRB1*03, A*29-DRB1*07, A*24-DRB1*09, B*58-DRB1*03, B*08-DRB1*03, B*46-DRB1*09 were significant positive linkage disequilibrium in Ewenki nationality group. The distribution of HLA A,-B, DRB1, alleles haplotypes frequencies and phylogenetic tree indicated that the Oroqen and Ewenki population groups belongs to northern group of China, together as a group cluster.     

The polymorphism and haplotype analysis of HLA-A, -B and -DRB1 genes of population in Jiangsu province of China

The polymorphism of human leucocyte antigen (HLA)-A, -B and -DRB1 genes and their computed haplotype analysis results from a population of Jiangsu province of China are presented here. The data consist of 20 248 unrelated peripheral blood stem cell donors in Jiangsu Branch of Chinese National Marrow Donor Program registry. In total, 18 different HLA-A alleles, 34 different HLA-B alleles and 13 different HLA-DRB1 alleles were found in Jiangsu Han population. The most frequent alleles in HLA-A, -B and -DRB1 loci were A*02 (29.55%), B*15 (14.40%), and DRB1*09 (16.15%), respectively. The most common haplotype in A-B-DRB1 loci was A*30-B*13- DRB1*07 (6.92%), in A-B loci was A*30-B*13 (8.05%), in B-DRB1 loci was B*13-DRB1*07 (8.17%), and in A-DRB1 loci was A*02-DRB1*09 (8.30%). The dendrogram study indicated that the distribution of HLA genes in Jiangsu Han population, as expected, represented a mixture of Northern and Southern Han population in China. These findings could shade new lights in population genetics and anthropology studies of Han-Chinese.     

HLA-A, HLA-B, and HLA-DRB1 alleles and haplotypes in Naxi and Han populations in southwestern China (Yunnan province)

The frequencies of the human leukocyte antigen alleles HLA-A, HLA-B, and HLA-DRB1 and the A-B-DRB1, A-B, and B-DRB1 haplotypes were studied in Naxi and Yunnan Han populations using polymerase chain reaction (PCR)-sequence-specific amplification for alleles A and B and a PCR-microtiter plate hybridization method for the DRB1 allele. A total of 8 A, 19 B, and 30 DRB1 alleles were found in the Naxi population, and 15 A, 21 B, and 36 DRB1 alleles were found in Yunnan Han population. The common A-B-DRB1 haplotypes in the Naxi population were A*24-B*15-DRB1*1202, A*11-B*15-DRB1*0405, A*11-B*15-DRB1*1202, A*11-B*38-DRB1*08032, and A*11-B*55-DRB1*0405; the common A-B haplotypes were A*11-B*15, A*11-B*38, and A*24-B*15; and the common B-DRB1 haplotypes were B*15-DRB1*1202, B*38-DRB1*08032, and B*48-DRB1*1201. In the Yunnan Han population, the common A-B-DRB1 haplotypes were A*24-B*15-DRB1*1501, A*24-B*46-DRB1*08032, and A*24-B*15-DRB1*1201; the common A-B haplotypes were A*24-B*15, A*24-B*46, and A*34-B*46; and the common B-DRB1 haplotypes were B*15-DRB1*1501, B*46-DRB1*09012, and B*46-DRB1*1401. Phylogenetic tree and principal component analyzes based on HLA-A, HLA-B, and DRB1 allele frequencies suggested that the Naxi ethnic group belongs to the southern Chinese groups, while the Yunnan Han population is a characteristic population located intermediate between northern and southern Chinese groups, although they live in the southwest of China.     

山西汉族人群HLA-A、-B、-DRB1基因多态性研究

目的 调查山西汉族人群HLA-A、-B、DRB1基因多态性，获得完整准确的遗传学数据。方法 应用聚合酶链反应，序列特异性引物方法对7440名健康、无血缘关系的山西汉族个体进行HLA—A、-B、-DRB1基因型检测，并与不同人群等位基因进行比较。结果 检出A等位基因18个，B等位基因40个，DRB1等位基因13个，其中A＊02、A＊24、A＊11、A＊01、A＊03、B＊13、B＊51、B＊15、B＊40、B＊35、DRB1＊15、DR＊09、DR＊1：2、DR＊04、DR＊07等位基因频率分布较高。结论 山西汉族人群HLA—A，-B，-DRB1基因具有中国北方汉族人群共有的遗传特征，但也有其自身的分布特点。     

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.     

Polymorphism of human leukocyte antigen-A, -B, and -DRB1 in a Moroccan population from Casablanca: study of the allelic and the haplotypic frequencies

We have studied the distribution of HLA-A, -B and DRB1 alleles and haplotypes by sequence specific oligonucleotide amplification in a sample of 125 unrelated healthy Moroccan individuals from Casablanca in Morocco. The city of Casablanca is known of its big ethnic diversity, especially Arabs and Berbers. The most frequent alleles found were: HLA-A*02 (18.4%), -A*01 (11.2%), -A*03 (10.8%), -B*51 (8.06%),-B*44 (7.66%), -B*08 (6.85%), -DRB1*04 (15.98%), DRB1*03 and DRB1*07 (13.92%) and -DRB1*01 (10%). High frequency for five two-locus haplotypes was observed for A*03-B*51 (5%), A*02-DRB1*03 (5.5%), A*02-DRB1*04 and A*01-DRB1*04 (5%) and B*35-DRB1*04 (4%). No predominant haplotype was observed for HLA A-B-DRB1. Our results confirm and extend the current knowledge about genetic pattern of the Moroccan of Casablanca. This study will serve as a reference for further anthropological studies, as well as studies of HLA and disease associations in the Moroccan population.     

HLA-B*07 allele frequencies and haplotypic associations in Koreans

We have investigated the frequencies of HLA-B*07 alleles and their haplotypic associations with HLA-A, -C and -DRB1 loci in 489 healthy unrelated Koreans, including 214 parents from 107 families. All of the 45 samples (9.2%) typed as B7 by serology were analyzed for B*07 alleles using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) method. Two different B*07 alleles were detected: B*0702 (allele frequency 0.041) and B*0705 (0.005). Two characteristic haplotypes showing strong linkage disequilibrium in Koreans were A*2402-Cw*07-B*0702-DRB1*0101 (haplotype frequency 0.028) and A*2901-B*0705-DRB1*0803 (0.005). The characteristic haplotype A*2901-B*0705-DRB1*0803, found in 100% (5/5) of B*0705-positive individuals, has not been previously described in other ethnic groups. HLA-B7 alleles comprise distinctive extended haplotypes in the Korean population. The probability of HLA-B7 allele mismatches among ABDR-matched unrelated donor-recipient pairs is expected to be low in Koreans.