一例稀有CisAB血型血清学及遗传机理分析

目的对1例献血者血型血清学鉴定为A2B血样进行基因型分析。方法应用常规血型血清学方法进行血型鉴定;采用PCR-SSP法进行ABO初步基因分型的检测,并对ABO基因第6和第7外显子的核苷酸序列进行扩增、测序和分析。结果血型血清学鉴定为A2B亚型,基因分型为BB型,初步判定为B(A)型;基因测序发现两条等位基因第6外显子均不存在261delG及297 G/G,判定该献血者血型为B与B基因的组合,经与A101核苷酸序列比对,对第7外显子的核苷酸序列分析发现,有一条核苷酸链上有526C>G,657C>T、703G>A及803G>C点突变,另一条核苷酸链上有297A>G、526C>G、657C>T、703G>A、796C>A、803G>C及930G>A点突变,确定该献血者血型基因型为CisAB02/B101。结论血型血清学对CisAB和B(A)判定有一定的局限性,通过核苷酸序列及分析能够明确本例献血者基因型为CisAB02/B101。

Serology and genetic mechanism of a rare case of CisAB blood group

Objective To analyze the genotype of a sample identified as subtype A2B.Methods Blood group was identified by routine serological technique,while primary ABO grouping was performed by PCR-SSP method.The nucleotides of exons 6 and 7 of ABO gene were amplified,cloned and sequenced.Results The sample from donor was identified as subtype A2B,genotype BB,and was primarily judged as type B(A).No 261delG or 297 G / G was found in exon 6 of two alleles by gene sequencing,indicating the blood group of the donor as combination of B and B genes.The nucleotide sequence alignment with the A101 showed point mutations of 526C > G,657C > T,703G > A,803G > C in one nucleotide chain of exon 7,and point mutations of 297A > G,526C > G,657C > T,703G > A,796C > A,803G > C,930G > A in the other nucleotide chain.The genotype of the sample was defined as CisAB02 / B101.Conclusion There are some limitations in serological test for identification of types CisAB and B(A) which may be distinguished clearly by nucleotide sequencing.The genotype of case in this paper was defined as CisAB02 / b101 by nucleotide sequencing.