Alaez C, Vázquez-García M N, Gorodezky C
Department of Immunogenetics. Instituto de Diagnóstico y Referencia Epidemiológicos, InDRE, SSA, Mexico.
Genes Immun. 2001 Jun;2(4):216-21. doi: 10.1038/sj.gene.6363765.
The upstream sequences in the 5' flanking region of HLA class II genes, regulate their expression and contribute to the development of immunological diseases. We analyzed 105 healthy unrelated Mexican Mestizos for QAP and QBP polymorphism. DNA typing for DRB1, DQA1, DQB1, QAP1 and QBP1 was done using a standardized PCR-SSOP. Although all QAP alleles previously described were found in Mexicans, the distribution differed as compared to other populations. QAP-3.1, 4.1 and 4.2 were the most frequent alleles and were associated with DQA103, 0501 and 0402 respectively. The prevalent QBP alleles were 3.21, 3.1 and 4.1 found mainly associated with DQB10302, 0301 and 0501. Linkage disequilibria between the promoter and the corresponding DQA1 and DQB1 allele, are in general the same as described by others. A total of 61 different haplotypes were defined, only six of them with a frequency above 4%. The haplotypes DRB10407-QAP-3.1-DQA103-QBP-3.21-DQB10302 (HF = 14.37%) and DRB10802-QAP-4.2-DQA10401-QBP-4.1-DQB10402 (HF = 14.22%), which have an Amerindian ancestry, are the most frequent in Mexicans. Some rare combinations were detected such as DRB10405-QAP-1.3-DQA10101/4-QBP-5.11/5.12-DQB10501 and DRB10403-QAP-3.2-DQA103-QBP-3.21-DQB10302, probably due to ancient recombination events. This knowledge is relevant as a basis to evaluate functional implications and to explore the role of promoter diversity in disease expression.
人类白细胞抗原（HLA）II类基因5'侧翼区域的上游序列调控其表达，并与免疫疾病的发生发展相关。我们分析了105名健康的墨西哥混血非亲属个体的QAP和QBP多态性。使用标准化的聚合酶链反应-序列特异性寡核苷酸探针（PCR-SSOP）对DRB1、DQA1、DQB1、QAP1和QBP1进行基因分型。虽然之前描述的所有QAP等位基因在墨西哥人中均有发现，但与其他人群相比，其分布有所不同。QAP-3.1、4.1和4.2是最常见的等位基因，分别与DQA103、0501和0402相关。常见的QBP等位基因是3.21、3.1和4.1，主要与DQB10302、0301和0501相关。启动子与相应的DQA1和DQB1等位基因之间的连锁不平衡，总体上与其他人描述的相同。共定义了61种不同的单倍型，其中只有6种频率高于4%。具有美洲印第安人血统的单倍型DRB10407-QAP-3.1-DQA103-QBP-3.21-DQB10302（高频 = 14.37%）和DRB10802-QAP-4.2-DQA10401-QBP-4.1-DQB10402（高频 = 14.22%）在墨西哥人中最为常见。检测到一些罕见的组合，如DRB10405-QAP-1.3-DQA10101/4-QBP-5.11/5.12-DQB10501和DRB10403-QAP-3.2-DQA103-QBP-3.21-DQB1*0302，可能是由于古老的重组事件。这些知识对于评估功能影响以及探索启动子多样性在疾病表达中的作用具有重要意义。
