Tchinda Joëlle, Lee Charles
Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Biotechniques. 2006 Oct;41(4):385, 387, 389 passim. doi: 10.2144/000112275.
Among human beings, it was once estimated that our genomes were 99.9% genetically identical. While this high level of genetic similarity helps to define us as a species, it is our genetic variation that contributes to our phenotypic diversity. As genomic technologies evolve to provide genome-wide analyses at higher resolution, we are beginning to appreciate that the human genome has a lot more variation than was once thought. Array-based comparative genomic hybridization (CGH) is one of these technologies that has recently revealed a newly appreciated type of genetic variation: copy number variation, in which thousands of regions of the human genome are now known to be variable in number between individuals. Some of these copy number variable regions have already been shown to predispose to certain common diseases, and others may ultimately have a significant impact on how each of us reacts to certain foods (e.g., allergic reactions), medications (e.g., pharmacogenomics), microscopic infections (i.e., immunity), and other aspects of our ever-changing environment.
曾经有人估计，人类基因组的基因相似度为99.9%。虽然这种高度的基因相似性有助于将我们定义为一个物种，但正是我们的基因变异造就了我们的表型多样性。随着基因组技术不断发展，能够以更高分辨率进行全基因组分析，我们开始认识到人类基因组的变异比以前认为的要多得多。基于阵列的比较基因组杂交（CGH）就是其中一项技术，它最近揭示了一种新发现的基因变异类型：拷贝数变异，现在已知人类基因组中有数千个区域在个体之间的数量是可变的。其中一些拷贝数可变区域已被证明易患某些常见疾病，其他区域最终可能会对我们每个人对某些食物（如过敏反应）、药物（如药物基因组学）、微生物感染（即免疫力）以及不断变化的环境的其他方面的反应产生重大影响。
