中国汉族个体HLA全长序列新等位基因A＊74：02：01：02的鉴定

目的对中国汉族个体人类白细胞抗原（HLA）-A基因全长序列进行测定，发现和鉴定突变位于常规检测区域以外的全长序列新等位基因。方法应用已对常规检测区域第2～4外显子进行测序分型、结果已知的中国汉族个体的样本进行HLA—A基因全长4．3kb序列的高保真扩增、克隆及测序；利用序列比对、进化树等方法分析突变所在位置及其产生的原因。结果发现1个HLA—A全长序列新等位基因，序列与国际IMGT／HLA数据库中最接近的等位基因A＊74：02：01：01的全长序列相比共有5个位于内含子的变异，其中第3内含子1个：NT1427C〉T，第7内含子5个，分别为NT2842G〉A，NT2850C〉T，NT2862T〉C，NT2863G〉A以及NT2868T〉C。该HLA—A新等位基因于2010—07—31被世界卫生组织人类白细胞抗原因子命名委员会正式命名为HLA—A＊74：02：01：02。结论新等位基因A＊74：02：01：02的变异产生的机制可能是随机突变和等位基因之间的交换重组。

Identification of a Genomic Full-Length Novel Allele A * 74 : 02 : 01 : 02 From a Chinese Han individual

Objective To determinate the human leukocyte antigen （HLA）-A genomic full length sequence, in order to discover and identify the novel allele which has the mutation outside the regular-typing region in Han Chinese individual. Methods The 4. 3 kb genomic full-length HLA-A sequences of the Chinese Han individual, that has been typed on exon 2-4, were high-fidelity polymerase amplified, cloned and sequenced. The sequence alignment and the phylogenetic analysis were used to clarify the variations and their origins. Results A full-length novel allele of HLA-A was identified, which had 6 nucleotide variations in introns from its closest allele A ＊ 74：02：01：01 in IMGT/HLA database. One variation （NT1427C~T） located in intron 3, and other 5 variations （NT2842G〉A. NT2850C〉T, NT2862T〉C, NT2863G〉A and NT2868T〉C） located in intron 7. The novel allele named A ＊ 74：02：01;02 has been officially assigned by the World Health Organization （WHO） Nomenclature Committee for Factors of the HLA System. Conclusions The mechanisms which produce variations of novel allele A ＊ 74：02 ： 01 ： 02 may be random mutation and allele reeombinate.