B(A)04亚型血清学与分子生物学鉴定及与其他AB亚型的鉴别要点

Research on serology and genetics of B(A)04 subtype and identification with other AB subtype

目的对3例血清学定性为A_(weak) B亚型的血标本进行ABO基因检测,探讨其分子遗传学特点,并探讨B(A)亚型与CisAB、A亚B型的鉴别要点。方法用PCRSSP对常规血清学方法定型困难的3例标本进行ABO基因分型,并对其ABO基因第6、7外显子扩增后进行直接测序及单倍型测序,确定其基因型。结果3例标本血型血清学结果均为A_(weak) B型,存在不规则抗A抗体。基因分型均为B(A)04型,其B等位基因在第7外显子存在nt640A>G突变,标本1为B(A)04/O02,标本2、3为B(A)04/O01。结论当血清学检测结果正反定型不一致时,应采用分子诊断技术进行辅助诊断,并采用配血相合输血策略,可确保临床输血安全。

Objective To detect A_(weak) B subtype of ABO gene in three blood sample,discuss the molecular genetic basis and briefly explore the key points of identification for CisAB with B(A)subtype.Methods PCRSSP was employed for ABO genotyping of 3 blood samples with difficult identification by routine serological methods.The genotypes of the 3 samples were determined by direct and haplotype sequencing for the products of amplification of the complete regions of exons 6 and 7 in ABO blood group gene,and their alleles were also identified.Results The results of the serologic group of the three samples were all A_(weak) B type with irregular antiA antibodies.The genotype was all B(A)04.The sample 1 was B(A)04/O02 and both sample 2 and 3 were B(A)04/O01.The B alleles were present nt640A>G mutation in exon 7 and was confirmed as B(A)04 allele.Conclusion When the positive and negative results of serological tests are inconsistent,molecular diagnostic techniques should be used for auxiliary diagnosis,and matching compatibility for blood transfusion strategy should be adopted,to ensure the the safety in clinical transfusion.