广东汉族人群HLA单倍型遗传中基因重组的研究

Recombination of HLA haplotypes in Guangdong Han nationality

目的 分析广东汉族人群人类白细胞抗原（HLA）Ⅰ、Ⅱ经典5位点A、Cw、B、DRB1及DQB1的连锁单倍型及单倍型遗传中基因重组事件.方法 采用聚合酶链反应-序列特异性寡核苷酸探针（PCR-SSO）法及聚合酶链反应-序列特异性引物（PCR-SSP）法,分别对2000年8月至2009年12月深圳市血液中心进行HLA配型的198个广东汉族家系共939名个体的外周血样本进行HLA-A、B、DRB1位点及HLA-Cw、DQB1位点的低分辨基因分型,再通过遗传家系分析确定HLA基因重组相关位点 对其中发生基因交换重组的52名家系成员的样本进一步采用基因测序分型（SBT）技术进行序列分析,以判断重组交换是否发生在某基因座位上.结果 198个广东汉族家系543名子一代个体中,发现有9名个体HLA单倍型基因座位发生了交换重组,频率为1.657%.3例为A/Cw座位间的交换,6例为B/DRB1座位间的交换.其中4例重组事件发生在广东汉族人群最常见的单倍型A＊3303-Cw＊0302-B＊5801-DRB1＊0301-DQB1＊0201上.在9例重组事件中有5例来自母系染色体交换,4例来自父系染色体交换 3例表现为A/Cw座位间交换的个体均为女性,6例表现为B/DRB1座位间交换的个体中5例为男性、1例为女性.结论 HLA连锁单倍型遗传过程中的基因重组主要见于A/Cw座位间及B/DRB1座位间,且基因重组的发生具有单倍型特异性及性别特异性.

Objective To analyze the human leukocyte antigen complex class Ⅰ （-A, -B ＆ -C）and class Ⅱ （-DRB1 ＆ -DQB1） linked haplotypes of Guangdong Han nationality and to study the recombination events of five classical loci in the inheritance of HLA haplotypes. Methods A total of 939 peripheral blood samples were collected from 198 families in Guangdong Han nationality who came to our center for HLA typing from 2000 August to 2009 December. HLA-（ A, B ＆ DRB1 ） and HLA-（ C ＆ DQB1 ）alleles were typed by low-resolution polymerase chain reaction-sequence specific oligonucleotide probes （PCR-SSO） and PCR-sequence specific primers （PCR-SSP） methods respectively. Then the recombination sites were analyzed by familial study. The samples of 52 individuals from the families with exchange recombination were analyzed by the sequence-based typing （SBT） to judge whether the recombination was interallelic or interlocus exchange. Results Among 543 offspring individuals of 198 families in Guangdong Han nationality, 9 individuals with HLA-A-C-B-DRB1-DQB1 linked haplotypes had a recombination rate of 1. 657%. Among 9 HLA haplotypes recombined families, 3 of them were found to have a crossover between HLA-A and -Cw loci and 6 of them a crossover between HLA-B and -DRB1 loci. Four of these recombination events occurred in the most common haplotypes A ＊ 3303-Cw ＊ 0302-B ＊ 5801-DRB1 ＊ 0301-DQB1 ＊ 0201of Guangdong Han nationality. Among 9 cases of recombination, 5 of them were formed by a crossover between maternal chromosomes and 4 cases a crossover between paternal chromosomes. Three individuals with an exchange between A/Cw loci were all females. Among 6 cases with an exchange between B/DRB1 loci, 5 of them were males and 1 case was female. Conclusion During the inheritance, recombination of HLA linked haplotype mainly occured between A /Cw loci and B/DRB1 loci, the recombination is related to the haplotype-specificity and sex-specificity.