序列分析及确认HLA新等位基因B*55:46

背景：近几年来，随着中华骨髓库的建立和人类白细胞抗原分型技术的不断发展和提高，中国人类白细胞抗原新等位基因不断被发现。目的：探索中国人的人类白细胞抗原新等位基因。方法：应用PCR-序列特异性寡核苷酸探针基因分型技术，对1名27岁男性汉族造血干细胞志愿捐献者进行HLA基因分型，并应用基于测序的方法分析该基因序列及与最相近等位基因序列的差异。结果与结论：PCR-序列特异性寡核苷酸探针结果显示该样本HLA-B基因座反应格局出现异常提示；基因测序结果表明其B基因座第3外显子序列与所有已知HLA-B等位基因序列均不一致，在所检测的第2、3外显子中，与序列最相近的等位基因B*55:02:01的差异只是在第3外显子发生了nt 412 A→G一个核苷酸替代，导致第138位密码子由AAC→GAC，相应的编码的天冬酰胺改变为天冬氨酸。将其序列提交国际基因数据库及IMGT/HLA 数据库，证实该HLA等位基因为国际上首次发现，被世界卫生组织织人类白细胞抗原因子命名委员会正式命名为HLA-B*55:46 (HM989018)。

Sequence analysis and identification of a novel allele,HLA-B*55:46

BACKGROUND:In recent years, with the development of China Marrow Donor Program and the improvement of human leukocyte antigen (HLA) typing technique, novel HLA alleles have been discovered constantly in China. OBJECTIVE:To identify and confirm a novel HLA allele in a Chinese individual. METHODS:A new HLA allele was found in a 27-year-old male Han volunteer donor of hematopoietic stem cells during routine HLA genotyping by PCR-sequence specific oligonucleotide probes and sequencing-based typing. RESULTS AND CONCLUSION:The HLA-B locus hybridization probe reaction patterns of this sample did not match to any known HLA-B alleles or allelic combinations. Exons 2-3 were sequenced in both directions using HLA-B sequence primer and group-specific sequencing primer. The new sequence had 1 nt change from its closest allele B*55:02:01 at nucleotide 412 where A→G (codon138 AAC→GAC) resulting in a coding change,  138 Asparagine (N) was changed to Aspartate (D). The nucleotide sequence has been submitted to the GenBank nucleotide sequence database and it is available under the accession number HM989018. A novel HLA allele, HLA-B*55:46, has been identified, and named officially by the WHO Nomenclature Committee.