B（A）血型分子机制研究及其家系分析  

Molecular basis of the B （A） phenotype and its pedigree analysis

作　　者：洪小珍[1] 许先国[1] 马开荣[1] 兰小飞[1] 朱发明[1] 严力行[1] 

机构地区：[1]浙江省血液中心卫生部血液安全研究重点实验室,杭州310006

出　　处：《中华检验医学杂志》2010年第1期51-55,共5页Chinese Journal of Laboratory Medicine

基　　金：国家自然科学基金资助项目（30772065、30871112）;浙江省医药卫生科学研究基金资助项目（2007A044）

摘　　要：目的研究罕见B（A）血型的血清学特性和分子机制，为B（A）血型的临床输血提供理论基础。方法利用单克隆抗体检测1例先证者、家系成员及献血者红细胞ABO血型抗原，用标准A、B、O红细胞检测其血清中的ABO抗体。采用盐水法、凝聚胺法和抗球蛋白法进行先证者与献血者交叉配合试验。采用PCR技术扩增ABO基因的第6、7外显子序列，对先证者、家系成员、献血者标本的ABO基因外显子6、7和侧翼内含子序列进行测序分析，并对先证者标本进行单倍体序列分析。结果先证者及其2位家系成员红细胞上有A、B抗原，同时血清中存在抗A1抗体，血清学表型为A2B。直接测序分析发现先证者标本第6、7外显子存在261G／del、297A／G、526C／G、657C／T、700C／G、703A／G、796A／C、803G／C、930A／G杂合，可推断为B（A）02／O01基因型杂合子；家系中其母亲基因型为B（A）02／B101，外祖母为B（A）02／O01.先证者单倍体序列分析得到2个等位基因B（A）02：和O01；与B101序列相比，B（A）02第700位C〉G，导致1个氨基酸改变：第234位脯氨酸变成丙氨酸。既往血清学特性为A：B的2个献血者，1个基因型为B（A）02／O01，另1个基因型是A208／B101.B（A）血型先证者与这2名献血者进行交叉配血试验均相合，临床输注后无不良反应。结论α-1，3-半乳糖基转移酶等位基因（B等位基因）700C〉G突变可导致形成B（A）血型，其血清学特性显示为A2B表型。B（A）血型临床输血相配合的供者可选择A，B表型的献血者。Objective To investigate the serological characteristics and molecular basis of the B （A） phenotype in ABO blood group and provide the data for clinical transfusion of individuals with B （A） phenotype. Methods The ABO group antigens on red cells of the proband, family members and donors were identified by monoclonal antibodies and the ABO antibodies in sera were detected by the standard A, B, O cells. The compatibility testing for the proband and donors was detected by salted test, polybrene test and antiglobalin test. The coding region of exon 6 to exon 7 in ABO gene was amplified by polymerase chain reaction （PCR） and the PCR products were sequenced. The haplotypes of proband were analyzed by cloning and sequencing. Results It was showed that both A and B antigens were detected on red cells of the proband and her two family members, and there was anti-A1 antibody in their sera. The serological phenotype of the samples are identified as the A2B. DNA sequencing showed 261G/del, 297A/G,526C/G, 657C/T, 700C/G, 703G/A, 796C/A, 803G/C, 930G/A heterozygotes in exon 6 to exon 7. It can be deduced that genotype in the proband is B（A）02/O01. The genotypes of her mother and grandmother-in-law were B （A） 02/B101 and B （A） 02/O01, respectively. After cloning and sequencing, two alleles B （A） 02 and O01 in proband was showed. B（A）02 has snigle nucleotide change （700 C 〉 G）, which results replacement of proline with alanine at position 234. Two donors with phenotype A2 B were identified as genotype B （A）02/ O01 and A208/B101, respectively. The results of crossmatch testing is in accordane between the proband and two donors and there was no clinical adverse reaction after transfusion. Conclusions 700C 〉 G in α-1, 3 galactosyhransferase allele （B allele） can result in B （A） phenotype in individuals with the phenotype of A2B. The donors in the transfusion for the individuals with B（A） phenotype should include individuals with A2 B phenotype.

关 键 词：ABO血型系统 血型不合 系谱 

分 类 号：R446.6[医药卫生—诊断学]