一个Bw亚型家系的血型分子机制及临床输血分析

Molecular basis and clinical transfusion of a family with Bw subtype of ABO blood group system

目的对1个Bw亚型血型家系的分子机制进行研究，并探讨该亚型的临床输血情况。方法对1名AB0血型正反定型不符的无偿献血者及其家人的血型进行血清学鉴定，并应用聚合酶链反应一序列特异性引物法、AB0基因直接测序、TA克隆单倍型分析及相关软件对该突变引起的酶结构及功能变化进行分析等方法，同时对该献血者以往3次所献的血样的临床输血情况进行回顾。结果在该家系中发现了3例较为罕见的Bw亚型。该亚型是由于AB0基因第7外显子存在721C／T杂合，导致R241W氨基酸改变所致。临床回顾提示3次输血均未发现明显异常。结论AB0基因721C〉T突变是导致Bw亚型的分子遗传基础之一，该亚型在临床输血中的意义尚需进一步探讨。

Objective To study a family with Bw subtype of ABO blood group system, and to review safety issues in relation with clinical transfusion. Methods The molecular basis for the blood type was studied with serological assay, polymerase chain reaction-sequence specific primer （PCR-SSP） and DNA sequencing, TA clone and haplotype analysis in one blood donor whose ABO blood group were difficultly typed and her family. The bioinformatics analysis was carried out by biological analysis software to investigate the change of structure and function of enzymes influenced by the change amino acid. A retrospective survey was carried out to investigate what is the actual position that the donor blood was used in the clinical transfusion. Results Three members from the family were found to have a Bw subtype. A substitution of nucleotide C by T at position 721 in exon 7 was discovered, which resulted in replacement of amino acid Arg to Trp. Review of clinical record suggested that there has been no significant abnormality association with past three blood transfusions. Conclusion A 721C〉T mutation of the ABO gene probably underlies the Bw subtype. Further research is needed for understanding the clinical significance of this subtype in the blood transfusion.