Abstract：
The GSTM1 and GSTT1 genes encode homonymous enzymes, which are responsible for the detoxification of several substances potentially harmful to the human body, such as air pollution, drugs, pesticides, and tobacco. However, some individuals may present a complete deletion of these genes and, consequently, an enzyme deficiency leading to an inadequate metabolism and, therefore, a higher susceptibility to some clinical conditions. Interethnic variations have also been described for both genes, making necessary the study of the deletion frequencies of GSTM1 and GSTT1 in different populations around the world. So, the aim of this study was to enable the synthesis and discussion of the main population differences of GSTM1 and GSTT1 polymorphisms in healthy volunteers. Searches were performed in the PubMed database, including 533 articles and 178,566 individuals in the analyses. We found an overrepresentation of European individuals and studies, and an underrepresentation of non-European ethnicities. Moreover, there are significant frequency differences among distinct ethnic groups: East Asians present the highest frequencies worldwide for GSTM1 and GSTT1 deletions, which could suggest higher disorders risk for this population; in contrast, Sub-Saharan Africans presented the lowest frequency of GSTM1 worldwide, corroborating evolution inferences performed previously for other genes codifying metabolism enzymes. Also, admixture is a relevant component when analyzing frequency values for both genes, but further studies focusing on this subject are warranted.
摘要：
GSTM1和GSTT1基因编码同源酶，负责对几种可能对人体有害的物质进行解毒，比如空气污染，毒品,杀虫剂,和烟草。然而,有些人可能会出现这些基因的完全缺失，因此,酶缺乏导致代谢不足，因此,对某些临床疾病的易感性更高。也已经描述了这两个基因的种族间变异，有必要研究GSTM1和GSTT1在全球不同人群中的缺失频率。所以,本研究的目的是合成和讨论健康志愿者中GSTM1和GSTT1多态性的主要群体差异.在PubMed数据库中进行了搜索，分析中包括533篇文章和178,566人。我们发现欧洲人和研究人数过多，以及非欧洲种族的代表性不足。此外，不同种族之间存在显着频率差异：东亚人在全球范围内GSTM1和GSTT1缺失的频率最高，这可能表明该人群的疾病风险更高；相比之下，撒哈拉以南非洲人出现全球GSTM1的频率最低，先前对编码代谢酶的其他基因进行了确证进化推论。此外，当分析两个基因的频率值时，混合物是一个相关的成分，但是有必要对这一主题进行进一步的研究。
