HLA-B新等位基因B~*4608的核苷酸序列分析

目的分析1个HLA-B位点有异常反应格局样本的核苷酸序列。方法采用DNA快速抽提试剂盒抽提样本基因组DNA,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 TA克隆到质粒载体中以获得单链,对克隆所得产物进行HLA-B基因第2、3、4外显子双向测序分析。结果先证者样本克隆测序得到两个等位基因,其中1个等位基因为B*5502,另1个经Blast验证为新等位基因,其序列已递交Genbank(DQ177521,DQ177522,DQ177523)。与最接近的B*4601等位基因序列相比,新等位基因在第3外显子上有2个核苷酸不同,即第538位T→C和第539位G→T,并由此导致1个氨基酸改变:第156位色氨酸→亮氨酸。结论该新HLA-B等位基因已WHO HLA因子命名委员会正式命名为HLA-B*4608。

Sequences analysis for a novel HLA-B allele:HLA-B*4608

Objective To analyze the nucleotide sequences of novel allele HLA-B*4608. Methods Genomic DNA of the proband was extracted from whole blood by the commercial DNA extraction kit. The HLA-B exons 1-8 of the proband was amplified and the amplified product was cloned by TOPO TA cloning sequencing kit to split the two alleles apart. Both strands of exons 2, 3 and 4 of chosen colonies were sequenced. Results The sequencing results showed HLA-B alleles of the proband as B*5502 and a new allele as proved by blast search. The sequences of the novel allele have been submitted to Genbank(DQ177521,DQ177522,DQ177523). The new allele is similar to HLA-B*4601 except for two nucleotide substitutions in exon 3: T to C at nucleotide position 538 and G to T at nucleotide position 539. These result in an amino acid substitution at codon 156 from W to L. Conclusion This allele is a novel allele and has been officially named B*4608 by the WHO Nomenclature Committee.