新的HLA-B*4061等位基因的核苷酸序列分析

本研究探讨HLA新的等位基因HLA-B＊4061的分子基础。采用盐析法抽提样本DNA，利用PCR方法扩增先证者HLA-B基因的第1-8外显子，PCR产物直接经TOPO克隆到质粒载体中得到单链，对所得克隆进行HLA-B基因第2、3、4外显子双向测序分析。应用PCR-SSP方法证实测序所发现的突变。结果表明：先证者样本克隆测序得到2个等位基因，其中1个等位基因为B＋4601，另1个经blast验证其为新的等位基因，新的等位基因序列已递交GenBank（DQ089628，DQ089629，DQ089630）。与最接近的B＊400101等位基因序列相比，新的等位基因仅在第2外显子上有1个核苷酸不同，即第272位C→A，导致第67位氨基酸Ser→Tyr。结论：HLA-B＊4061等位基因为新的HLA-B等位基因，已荣获世界卫生组织HLA因子命名委员会正式命名。

Sequence Analysis of HLA-B*4061 Allele Newly Found

The aim of this study was aimed to investigate the molecular genetic basis for a novel HLA allele, HLA-B*4061, in Chinese population. DNA was extracted from whole blood by salting-out method. The HLA-B exons 1 - 8 of the proband was amplified and the amplified product was cloned using TOPO TA cloning sequencing kit to split the two alleles apart. Both strands of exons 2, 3 and 4 of chosen colonies were sequencing. The PCR-SSP was performed to confirm the mutations detected by sequencing. The sequencing results showed HLA-B alleles of the proband as B*4601 and the novel allele. The sequences of the novel allele have been submitted to GenBank (DQ089628, DQ089629, DQ089630). After HLA blast analysis, the novel allele showed a single nucleotide mismatch with B*400101 in exon 2 at position 272 C-->A, as the results, changing amino acid from Ser to Tyr at codon 67. It is concluded that this allele is a novel one and has been officially named B*4061 by the WHO Nomenclature Committee.