首例HLA-B新等位基因HLA-B＊15：124的核苷酸序列分析

本研究探讨人类白细胞抗原（human leukocyte antigen,HLA）新等位基因HLA-B＊15：124的核苷酸序列及其分子机制。采用商用试剂盒抽提标本基因组DNA,利用HLA-B组特异性引物PCR扩增先证者HLA-B基因的第2,3和4外显子,经酶法纯化扩增产物后进行第2,3和4外显子双向测序分析。结果表明：先证者标本组特异性引物扩增测序得到2个等位基因,其中1个等位基因为B＊40：03,另1个为新发现的等位基因,与最接近的B＊15：52等位基因序列相比,新的等位基因在第3外显子上有2个核苷酸不同,第499位A→T和第512位G→T,这导致氨基酸第143位Thr→Ser和第147位Trp→Leu。结论：新的等位基因在第3外显子上有2个核苷酸不同。该等位基因序列已递交GenBank（EF187276）,并作为1个首次发现的HLA-B位点的等位基因,已经被世界卫生组织HLA因子命名委员会正式命名为HLA-B＊15：124。

Nucleotide Sequence Analysis of A Novel HLA-B*15:124 Allele Confirmed

This study was purposed to investigate the nucleotide sequences of a novel HLA-B＊15：124 allele and its molecular mechanism. The genomic DNA from whole blood was extracted by using commercial DNA extraction kit. The sequences of exon 2,3 and 4 of HLA-B locus in the proband were amplified by PCR with group-specific primers, the PCR products were purified by enzymes digestion, then exon 2 to 4 of HLA-B locus for both orientations was sequenced. The results showed that 2 HLA-B alleles of proband were gained after amplification and sequencing of group-specific primers, among them one was a B＊40：03, another was a novel allele. After BLAST analysis, the novel allele showed nucleotides different from HLA-B＊15：52 in exon 3 at nucleotide position 427 AT and 440 GT which resulted in amino acid change from Thr to Ser at codon 143 and Trp to Leu at conon 147. It is concluded that a novel HLA-B allele has two different nucleotides. This HLA-B allele is identified and has been officially named B＊15：124 by the WHO Nomenclature Committee.