罕见B(A)血型的分子遗传学研究

目的以核苷酸序列分析鉴定出血型血清学分型困难标本的ABO血型基因型。方法对常规血清学方法难以做ABO血型准确定型的3例被捡血样,采用PCR方法扩增其ABO等位基因的第6、7外显子,PCR产物采用直接测序和克隆测序的方法,以确定其基因型。结果 3例被检血样的血型血清学结果相似:红细胞与抗-A弱凝集,与抗-B强凝集,不与抗-A1凝集,其血清中存在抗-A,初步定型为AWB;经直接测序和克隆测序发现:3例被检血样都含有O等位基因,且它们的B等位基因在第7外显子都存在700CG突变,证实其为B(A)02等位基因。结论核苷酸序列分析证实这3例血清学表现为AWB亚型个体均为B(A)表现型,基因型均为罕见的B(A)02/O型。

Molecular analysis of rare B(A) blood group

Objective To determine the genotypes of the blood samples with serological typing difficulty through DNA sequencing analysis.Methods Complete exon 6 and 7 in the ABO genes of three inaccurately typed blood samples by routine serological methods were amplified by PCR.The PCR products were directly sequenced and cloning sequenced to identify its genotype.Results The serological results of three blood samples were similar: red cells were strongly agglutinated by anti-B,weekly agglutinated by anti-A,and not agglutinated by anti-A1;the serum contained anti-A.They were preliminarily typed as AWB.Results of the sequencing analysis showed the three samples harbored an O allele,and had the nt700C>G mutation in the B gene,which was previously defined as B(A)02.Conclusion Through sequencing analysis,the three samples which have been typed as AWB in serological tests are identified as B(A) phenotype.Their genotypes are rare B(A)02/ O.