人类白细胞抗原新等位基因B*46∶01∶18的确认及家系调查

摘要

目的 鉴定一个人类白细胞抗原(human leukocyte antigen,HLA)B位点的新等位基因,并调查其家系遗传情况.方法应用聚合酶链反应-基于测序的分型技术(polymerase chain reaction-sequence based typing,PCR-SBT)进行HLA常规实验分型,HLA-B位点分型结果与等位基因B* 46∶01∶01,B* 15∶25∶01在384位有一个碱基不匹配,不能指定为任何HLA-B位点等位基因.用针对B*46、B*15的组特异性测序引物,确认与同源性最高的HLA等位基因序列的差异,并对先证者家系进行调查.结果 测序结果证实,该等位基因与其同源性最高的等位基因是B*46∶01∶01,两者的差异是在第3外显子384位的G＞T,密码子104由GGG变为GGT,但是两者编码的氨基酸序列中104位仍然是甘氨酸(G).家系调查结果显示该新基因遗传自父亲.结论 该等位基因为HLA-B位点的一个新等位基因,世界卫生组织HLA命名委员会将其正式命名为HLA-B* 46∶01∶18,是在广西壮族人群中发现的新等位基因.%Objective To report on a novel human leukocyte antigen (HLA) allele.Methods Polymerase chain reaction-sequence based typing was used for routine HLA typing.For one sample,the result of B locus typing showed mismatch of one base with B * 46∶01∶01,B * 15∶25∶01 at locus 384.The group specific sequencing primers,which target at B * 46 and B * 15,were used to confirm the difference between the novel allele and the highest homologous allele.Results The sequencing results showed that the highest homologous allele to the novel allele was B * 46∶01∶01.The two sequences only differed for position 384 within the exon 3 (384G＞T),which resulted in a codon change (GGG＞GGT),though the amino acid sequence of the novel allele at position 104 was still Glycine (G).Investigation of the family showed that the novel allele was inherited from the father.Conclusion The novel HLA-B allele,discovered in ethnic Zhuangs from Guangxi,has been designated as HLA-B * 46∶ 01∶18 by the World Health Organization (WHO) HLA Nomenclature Committee.