本研究探讨ABO新等位基因O61的分子机制。利用单克隆抗体检测标本红细胞ABO血型抗原,标准A、B、O红细胞检测标本血清中的ABO抗体。采用聚合酶链反应(polymerase chain reaction,PCR)技术扩增ABO基因的第5至7外显子序列,PCR产物经双酶切后直接测序分析6和7外显子。1例B表型标本采用基因组单链抽提技术分离杂合基因型标本的2条单体型,对分离的单体型扩增后进行ABO基因测序分析。结果表明,在417例标本中发现3个标本743位碱基发生突变,其中2例表型为O型,1例为B型。2例O型直接测序分析显示,6和7外显子有261G缺失及743G/C杂合。1例B型直接测序结果为261G/缺失及297A/G、526C/G、743G/C、657C/T、703G/A、796C/A、803G/C、930G/A杂合。采用基因组单链抽提技术将B型标本的两条单体型进行分离,对分离的单体型扩增后进行ABO基因测序分析,结果显示,2条链分别为B101和突变的O型。将突变的新O型基因提交血型抗原基因突变数据库,被正式命名为O61。结论:ABO基因7号外显子743G>C为1个新的突变点,发现1个ABO新等位基因O61。 This study explored the molecular mechanism of the ABO new allele O61. ABO blood group antigens were detected by monoclonal antibodies and ABO antibodies were detected by standard A, B and O red blood cells. The exon 5 to exon 7 of ABO gene were amplified by polymerase chain reaction (PCR) technique. The PCR products were double-digested and sequenced for direct sequencing of exon 6 and exon 7. Two haplotypes of heterozygous genotypes were isolated by genomic single-stranded extraction in one case of B phenotype. The amplified haplotypes were amplified and sequenced. The results showed that mutations in the 743 bases of 3 specimens were found in 417 specimens, of which 2 were O type and 1 was B type. Two cases of O-type direct sequencing analysis showed that exons 6 and 7 had 261G deletion and 743G / C heterozygosity. One case of type B direct sequencing was 261G / deletion and 297A / G, 526C / G, 743G / C, 657C / T, 703G / A, 796C / A, 803G / C and 930G / A. Two haplotypes of type B were isolated by genomic single-stranded extraction. The isolated haplotypes were amplified and sequenced. The results showed that the two chains were B101 and mutant O-type, respectively. The mutation of the new O gene submitted to the blood group antigen gene mutation database, was officially named O61. Conclusion: ABO gene exon 7 743G> C is a new mutation point and found a new ABO allele O61.