DNA序列分析鉴定HLA新等位基因B*4446

目的鉴定中国人群的HLA新等位基因。方法使用PCR-序列特异性引物及PCR-序列特异性寡核苷酸探针技术进行HLA分型。发现1个与HLA-B*44相关的未知基因,使用DNA序列分析技术鉴定并分析该基因与同源性最高的B*4409基因序列的差异。结果新基因第3外显子区域序列与所有已知的HLA-B等位基因序列均不相同,与同源性最高的HLA-B*4409基因序列相比有3个碱基发生替代。第538位碱基由G→C,第539位碱基A→T以及第540位碱基C→G,使编码产物180位氨基酸由天冬氨酸变成亮氨酸。结论发现一个新的HLA-B等位基因,于2005年9月由WHOHLA因子命名委员会正式命名为HLA-B*4446。

Identification of a novel HLA allele B * 4446 by sequencing-based typing

OBJECTIVE: To identify a novel HLA allele in Chinese population. METHODS: A new HLA-B allele was initially detected by an usual PCR-SSP and PCR-SSOP in routine typing HLA allele. Sequence-based typing (SBT) was used to identify and analysis the difference between the new allele and HLA-B 4409 allele. RESULTS: The HLA-B exon 3 nucleotide sequence of the novel allele was different from all other known alleles. The allele had 3 nucleotides replaced of the closest matching B 4409 allele at nt538(G>C), nt539(A>T) and nt540 (C>G) in exon 3, resulting in an amino acid change from D(GAC) to L(CTG) at codon 180. CONCLUSION: A novel HLA allele was confirmed by the SBT and it was officially designated as HLA-B 4446 by WHO Nomenclature Committee for Factors of the HLA System in September,2005.