新的HLA-DRB1等位基因DRB1*1212的核苷酸序列分析

目的验证一个新的HLA等位基因HLA—DRB1＊1212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—DRB1＊090102，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DRB1＊120101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。结论该等化基因为新的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-DRB1＊1212。

Sequence analysis of a novel HLA-DRB1 allele,DRB1*1212

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.