B(A)血型家系的血清学及分子遗传学研究

摘要

目的 对1个ABO亚型正反定型不符的家系进行血型鉴定和分子遗传学分析,探讨其发生机制.方法 应用常规血清学方法 鉴定先证者及家系成员ABO血型,PCR方法 扩增家系成员ABO基因第6、7外显子,PCR产物采用直接测序方法检测基因型.结果 血清学方法检测先证者及其长子正反定型不符,初定为B(A)亚型;先证者丈夫及次子均为O型;测序结果显示先证者及其长子均检出O02等位基因,ABO基因第7外显子在B101基因基础上存在640 A＞G突变,符合B(A)04等位基因的特征,基因型为B(A)04/O02;先证者丈夫和次子基因型为O01/O02.结论 ABO基因第7外显子640 A＞G突变是形成B(A)04的分子遗传基础.%Objective To analyze the blood type of a family with B(A) blood type.Methods The serological blood type of the family was determined by routine tube method.Exons 6 and 7 of the ABO gene were amplified by PCR and subjected to Sanger sequencing.Results Serological testing of the proband and her elder son showed a discrepancy which was initially identified as B(A) subtype.Her husband and second son were identified as blood type O.Sequencing of the proband and her elder son has identified an O02 allele and a 640A＞G mutation compared with the B101 gene.Her husband and second son possessed the same genotype of O01/O02.Conclusion The 640A＞ G mutation of ABO gene probably underlies the B(A)04 subtype.