Boson W L, Romano-Silva M A, Correa H, Falcão R P, Teixeira-Vidigal P V, De Marco L
Departamento de Farmacologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Pharmacogenomics J. 2003;3(3):178-82. doi: 10.1038/sj.tpj.6500175.
Thiopurine methyltransferase (TPMT) catalyses the S-methylation of thiopurine drugs. Low-activity phenotypes are correlated with several mutations in the TPMT gene. Polymorphisms of TPMT have been reported for Caucasians, African-Americans and Asians. Since ethnic differences have been demonstrated worldwide, it remains to be elucidated in Brazil. The Brazilian population is the result of five centuries of interethnic crosses between peoples from almost all continents as well as autochthonous Amerindians, all forming the fifth largest and one of the most heterogeneous populations in the world. The frequency of six allelic variants of the TPMT gene, *2 (G238C) (2.2%), *3A (G460A and A719G) (1.5%), *3B (G460A) (0.2%), *3C (A719G) (1.0%), *5 (0%) and *6 (0%) were determined in Brazilian subjects using polymerase chain reaction (PCR)-RFLP and allele-specific PCR-based assays. This study provides the first analysis of TPMT mutant allele frequency in a sample of the Brazilian population.
硫嘌呤甲基转移酶（TPMT）催化硫嘌呤类药物的S-甲基化反应。低活性表型与TPMT基因的多个突变相关。已报道白种人、非裔美国人和亚洲人存在TPMT基因多态性。鉴于全球范围内已证实存在种族差异，巴西的情况仍有待阐明。巴西人口是近五个世纪以来几乎来自所有大陆的人群与本土美洲印第安人之间种族通婚的结果，所有这些构成了世界上第五大且最为多样化的人群之一。使用聚合酶链反应（PCR）-限制性片段长度多态性分析（RFLP）和基于等位基因特异性PCR的检测方法，在巴西受试者中确定了TPMT基因六个等位基因变体的频率，分别为*2（G238C）（2.2%）、*3A（G460A和A719G）（1.5%）、*3B（G460A）（0.2%）、*3C（A719G）（1.0%）、5（0%）和6（0%）。本研究首次对巴西人群样本中的TPMT突变等位基因频率进行了分析。
