新的HLA-DRB1等位基因DRB11212的核苷酸序列分析

Sequence analysis of a novel HLA-DRB1 allele,DRB11212

目的验证一个新的HLA等位基因HLA-DRB11212的序列。方法采用盐析法抽提样本基因组DNA,利用HLA-DRB1组特异性引物PCR扩增先证者HLA-DRB1等位基因的第2外显子,PCR产物经割胶回收后进行测序分析,通过聚合酶链反应-序列特异性寡核苷酸探针方法验证测序发现突变点。结果先证者有两个HLA-DRB1等位基因,其中一个为HLA-DRB1090102,另一个HLA-DRB1等位基因,经BLAST验证为新的等位基因,新的等位基因序列已递交GenBank(AY899825)。与最接近的DRB1120101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199位A→C,导致第67位氨基酸Ile→Leu。结论该等位基因为新的HLA-DRB1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-DRB11212。

Objective To investigate the molecular genetics basis for HLA novel allele HLA-DRB1＊1212 in Chinese population. Methods Genomic DNA was extracted from whole blood by salting-out method. HLA-DRB1 gene exon 2 was amplified by PCR with group-specific primers from genomic DNA. PCR products were cut back from agarose gels and purified to sequence directly. The polymerase chain reaction-sequence specific oligonucleotide probes（ PCR- SSO） was performed to confirm the mutations which were detected by sequencing in this study. Results The sequencing results showed HLA-DRB1 alleles of the proband as DRB1＊090102 and the novel allele. The sequences of the novel allele have been submitted to GenBank（AY899825）. Through BLAST analysis, the novel ＇allele was found to be different from DRB1＊120101 at position 199A→C in exon 2, that results in an amino acid change from Ile to Leu at codon 67. Conclusion This allele is a novel and has been officially named as DRB1＊1212 by the WHO Nomenclature Committee.