单个碱基变异致HLA-DQB1*03新等位基因的鉴定

Identification of a novel HLA-DQB1*03 allele caused by variant of a single nucleotide

目的确认1例HLA-DQB1新等位基因的序列,分析新等位基因的遗传学特征。方法应用PCR-序列特异性寡核苷酸探针分型技术(sequence-specific oligonucleotide probe,SSOP)及PCR-直接测序分型法(sequence-based typing,SBT)对1个白血病家系进行HLA常规检测,发现患者母亲及哥哥HLA-DQB1序列组合无完全匹配的基因型。应用二代测序(next generation sequencing,NGS)技术对该基因进行确认。结果PCR-SBT提示患者母亲及哥哥HLA-DQB1序列组合与已知基因型不完全匹配。NGS分析显示,与同源性最高的等位基因DQB1*03:02相比,该等位基因在第2外显子c.233T>G变异,导致46位编码氨基酸由缬氨酸变为甘氨酸(p.Val46Gly)。家系调查显示患者哥哥HLA-DQB1新等位基因来源于母亲。新等位基因序列已递交给GenBank数据库(MK729743)。结论应用NGS鉴定了1个HLA-DQB1新等位基因,该等位基因被世界卫生组织HLA因子命名委员会正式命名为HLA-DQB1*03:362。

Objective To delineate the characteristics of a novel HLA-DQB1 allele identified during routine HLA matching in a leukemia family.Methods The mother and brother of the patient was subjected to PCR sequence-specific oligonucleotide probe(SSOP),PCR sequence-based typing(SBT),as well as next-generation sequencing(NGS).Results PCR-SBT revealed that the patient’s mother and brother’s HLA-DQB1 sequence did not fully match with any known allele combination.NGS revealed that the novel allele differed from the closest matched DQB1*03:02 by a T>G substitution at position 233 in exon 2,which resulted in substitution of Valine at codon 46 by Glycine.Pedigree analysis confirmed that the novel HLA-DQB1 allele was inherited from his mother.Conclusion A novel HLA-DQB1 allele has been identified through next generation sequencing and was officially named as HLA-DQB1*03:362 by the World Health Organization HLA Factor Nomenclature Committee.