ABO亚型ABw07一家系的分子生物学研究

目的 研究一个ABO亚型ABw07家系的分子机制.方法 用单克隆抗体检测先证者红细胞ABO血型抗原.标准A、B、O红细胞检测先证者血清中的ABO抗体,采用聚合酶链反应技术扩增先证者ABO基因的第6和7外显子序列,PCR产物经酶切后直接测序分析.同时PCR产物经TOPO TA克隆到质粒载体中获得单链,对所得克隆进行ABO基因双向测序分析.家系调查采集先证者父母和姐姐的标本进行血型血清学实验和ABO基因第6和7外显子直接测序分析.结果 先证者红细胞有A、B抗原,同时血清中存在抗B抗体.直接测序分析发现第261位无缺失,第297位A/G、467C/T、526C/G、657C/T、703G/A、796C/A、803G/C、930G/A、1055C/A、1096A/G杂合,可推断为A102Bw07基因型.克隆测序得到两个等位基因A102和Bw07.与B101相比,Bw07第1055位G→A,导致1个氨基酸改变:第352位氨基酸精氨酸变成谷氨酰胺.家系调查显示先证者Bw07基因从母亲遗传所得,母亲血液标本ABO血型血清学特性和测序分析结果与先证者完全一致.结论 α-1,3-半乳糖基转移酶基因(B基因)第1055位G→A突变导致产生Bw07表型,其血清中可含有抗B抗体.

The molecular genetics basis for ABw07/phenotype of ABO subtype

Objective To analyze the molecular genetic basis for a case of ABw07 phenotype of ABO subtype.Methods The ABO group antigens on red blood cells of the proband were identified by monoclonal antibodies and the ABO antibody in serum was detected by the standard A,B and O cells.The exons 6 and 7 of the ABO gene was amplified by PCR and the PCR product was sequenced directly after enzyme digestion.The amplified product was also cloned by TOPO TA cloning sequencing kit to split the two alleles apart,chosen colonies were sequenced bidirectionaUy.The samples of the parents and one sister of the proband were collected,then the blood group serological test and sequence analysis for exon 6 to 7 of ABO genc were performed.Results Both A and B antigen were detected on red blood cells of the proband and there was anti-B antibody in the serum.There was no 261G deletion.And the 297A/G,467C/T,526C/G,657C/T,703G/A,796C/A,803G/C,930G/A,1055G/A and 1096A/G loci were heterozygotes by direct DNA sequencing,which can be assigned for A102Bw07 genotype.After cloning and sequencing,two alleles of A102 and Bw07/were obtained.The Bw07 has one nueleotide change of G to A at nueleotide 1055 compared with B101,which resuits in an amino acid change from Arg to Gin at nucleotide 352.The Bw07 in the proband was inherited from his mother,and the serological characteristic of the ABO blood group and the sequence of exons 6 and 7 of the mother were the same as that of the proband.Conclusion The G→A at nueleotide 1055 of α-1,3 galactosyltransferase gene (B gene)can result in BW7 phenotype,with anti-B antibody in serum.