一例ABO血型重组等位基因的分子特性

目的分析一例ABO血型重组等位基因的分子特性。方法ABO表型鉴定采用试管法。ABO基因和FUT1基因编码区序列检测采用PCR测序法。利用等位基因特异性引物扩增测序技术鉴别先证者ABO等位基因。先证者及其母亲ABO基因全长序列测定采用二代测序方法。结果先证者红细胞与抗H不凝集,FUT1基因为c.551_552del AG纯合,判定先证者为类孟买型。先证者ABO基因双链测序结果为c.261G/del、467C>T、c.526C>G、c.657C>T、c.703G>A、c.796C>A、c.803G>C、c.930G>A杂合。单链测序结果显示先证者有一个ABO*A1.02等位基因,另一个为ABO*O.01.01和ABO*B.01重组形成的等位基因。二代测序数据显示可能重组的位置在核苷酸c.375-269到c.526之间,家系分析显示先证者重组等位基因遗传自母亲。结论ABO血型等位基因存在重组现象。发现了1例ABO*O.01.01和ABO*B.01重组形成的新等位基因。

Molecular characterization of a recombination allele of ABO blood group

Objective To analyze the molecular characteristics of a recombinant allele of the ABO blood group.Methods The ABO phenotype was determined with the tube method.The coding regions of the ABO and FUT1genes were analyzed by PCR-sequence based typing.The ABO alleles of the proband were determined by allele-specific primer sequencing.The full sequences of the ABO gene of the proband and her mother were determined through next generation sequencing.Results The red blood cells of the proband did not agglutinate with anti-H,and the sequence of the FUT1 gene was homozygous for c.551_552delAG.The proband was thereby assigned as para-Bombay.Bi-directional sequencing also found that she was heterozygous for c.261G/del,467C>T,c.526C>G,c.657C>T,c.703G>A,c.796C>A,c.803G>C and c.930G>A of the coding regions of the ABO gene.Allele-specific primer sequencing also found her to carrya ABO*A1.02 allele and a recombinant allele from ABO*O.01.01 and ABO*B.01.The recombination site was located between nucleotidec.375-269 and c.526,and the allele was maternally derived.Conclusion An recombinant allele of the ABO genehas beenidentified,which has originated from recombination of ABO*O.01.01 with the ABO*B.01 allele.