Ael04亚型的鉴定与输血策略研究

Identification of Ael04 Bloodgroup and Transfusion Strategies

目的:探讨Ael04亚型的血清学和分子生物学特征及其安全输血策略。方法:应用常规血型血清学方法鉴定先证者及其家系成员ABO血型,测定血浆A糖基转移酶活性,采用PCR扩增ABO基因的全部外显子及侧翼的内含子序列后进行双向测序。结果:先证者血型正反定型不一致,血清学检测格局为A_(亚)、A_(亚)B,血浆中均未检出A酶活性。直接测序结果显示ABO基因在A102等位基因的基础上存在内含子6+5G>A的突变,符合ABO*AEL.04等位基因的特征。其中先证者1和先证者2基因型均为Ael04/O01,先证者1父亲基因型为Ael04/B101。结论:A等位基因内含子6+5G>A的突变,改变供者剪接位点,导致A酶活性缺失或显著减弱,红细胞表面A抗原弱表达,是Ael04亚型的形成原因。

Objective:To explore the serological feature,molecular mechanism and bloodtransfusion strategy of Ael04 subgroup in the ABO blood group system.Methods:Serological assay was carried out to determine the ABO blood group of the probands and their family members.Detection of the total plasma activity ofα-1,3-N-acetylgalactosaminyltransferase was conducted.All exons and flanking introns of the ABO gene were amplified with PCR and sequenced bidirectionally.Results:The discrepancies between forward and reverse blood grouping of the proband were found,suggesting the phenotype as Asub and AsubB.The A transferase activity in serum could not be detected with an in vitro assay.Direct sequencing show Intron 6+5G>A mutation in ABO*A1.02 allele,which was assigned as ABO*AEL.04 allele.The genotype of the proband 1and 2 was Ael04/O01,and the genotype of the proband 1’s father was Ael04/B101.Conclusion:The IVS6+5G>A mutation in the A allele that change the splice donor site may abolish or reduce the activity ofα-1,3-N-acetylgalactosaminyltransferase.It contributes to the weak A antigen expression on the surface of RBCs and resu lted in Ael04 bloodgroup.