HLA-B新等位基因B*9534的测序分析及其单链扩增技术的建立

目的 分析HLA-B新等位基因HLA-B*9534的核苷酸序列,并建立HLA-B * 9534单链扩增技术.方法 采用商品化快速抽提试剂盒抽提标本基因组DNA,采用PCR技术扩增先证者HLA-B基因的第1～8外显子序列,PCR产物经双酶切后直接测序分析第2、3、4外显子.应用序列特异性引物PCR建立HLA-B*9534单链扩增技术,获得HLA-B*9534等位基因的单链产物,并对单链产物进行第2、3、4外显子测序分析.结果 先证者标本存在2个HLA-B等位基因,直接测序结果经软件分析显示与最接近的HLA-B*1518和B*4601组合存在1个碱基不匹配,即第593位A/G杂合.单链扩增技术将先证者等位基因分离后,测序得到两个等位基因为HLA-B*4601和HLA-B*9534.与最接近的HLA-B*1518的第2～4外显子序列相比,HLA-B*9534仅在第3外显子存在一个碱基的不同,即第593位A→G的改变,导致第174位氨基酸天冬酰胺改变为丝氨酸,该等位基因序列已递交GenBank(EU046491),并经世界卫生组织HLA命名委员会正式命名为HLA-B*9534.结论 发现一个新的HLA-B*9534等位基因,建立的HLA-B*9534单链扩增技术是可行的.

Sequence analysis of a novel HLA-B * 9534 allele and establishment of group specific primers polymerase chain reaction method

Objective To analyze the molecular genetic basis of novel allele HLA-B * 9534 and establish the allele group specific primer PCR method. Methods Genomic DNA was extracted from whole blood by commercial DNA extraction kit. The HLA-B exons 1 to 8 coding sequences of the proband were am-plified by PCR and the amplification product was purified with double enzymes digestion and both strands of exons 2, 3 and 4 were sequenced. The exon 2-4 amplification of the HLA-B * 9534 was performed with al-lele group specific primers PCR and the PCR product was directly sequenced for exon 2 to 4. Results The proband has two HLA-B alleles. The result was assigned for HLA-B * 1518 and B * 4601 combination with a mismatch in 593A/G heterozygote by DNA sequencing of exon 2 to 4 with loci primers. After separating the two alleles of the proband with allele group specific primers polymerase chain reaction method, HLA-B * 4601 and HLA-B * 9534 alleles were identified after sequencing. The HLA-B * 9534 is identical to HLA-B * 1518 except for one nucleotide substitutions in exon 3 at position 593 A→G, this results in amino acid substitution at cedon 174 from Asn to Ser. The sequences of the novel allele have been submitted to GenBank (EU046491) and the allele has been officially nominated by the WHO Nomenclature Committee. Conclusion Identification of a novel HLA-B * 9534 allele and allele group specific primer PCR for HLA-B * 9534 was re-liable.