ABO血型新等位基因Ael08的分子生物学研究

目的研究ABO新等位基因Ael08的分子机制。方法利用单克隆抗体检测先证者标本红细胞ABO血型抗原,标准A、B、O红细胞检测血清中的ABO抗体,吸收放散试验检测红细胞上微量抗原;采用PCR技术扩增先证者ABO基因的第5~7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;扩增产物经TOPO TA克隆到质粒载体中获得单链,对所得克隆作ABO基因第6、7外显子双向测序分析;家系调查采集先证者父亲和哥哥的标本作血型血清学试验和ABO基因第6和7外显子直接测序分析。结果先证者红细胞上表达很弱的A抗原,只有通过吸收放散才能有效检出,同时其血浆中存在较强的抗-B和较弱的抗-A;直接测序分析发现:6号外显子第261位缺失杂合,7号外显子第297位A/G、467C/T、646T/A、681G/A、771C/T、829G/A、804insG/G杂合;克隆测序发现1个为常见的O02等位基因,另1个为1种新的等位基因(已被dRBC NCBI命名为Ael08),与A102比较,Ael08在第804位碱基处插入G,这导致氨基酸第268位后阅读框架发生改变,编码产物比正常A1转移酶多37个氨基酸。家系调查显示:先证者Ael08等位基因从父亲遗传所得。结论发现1个ABO新等位基因Ael08,α-1,3-N-乙酰半乳糖胺基转移酶基因(A基因)第804位碱基处插入G突变导致产生Ael表型。

Molecular basis of a novel allele Ael08

Objective To analyze the molecular genetic basis for Ael08 allele of ABO blood group.Methods The ABO group antigens on red blood cells of the proband were identified by monoclonal antibodies and the ABO antibody in serum was detected by the standard A,B,O cells.The weak antigen on RBCs was detected by absorption-elution test.Exon 5 to exon 7 encoding region of ABO gene was amplified by polymerase chain reaction(PCR) and the PCR product was sequenced directly for exon 6 and 7 after double enzyme digestion.Th...