Mao Rong, Pevsner Jonathan
Program in Biochemistry, Molecular, and Cellular Biology, Johns Hopkins School of Medicine, and Department of Neurology, Kennedy Krieger Institute, Baltimore, Maryland 21205, USA.
Ment Retard Dev Disabil Res Rev. 2005;11(4):279-85. doi: 10.1002/mrdd.20082.
Mental retardation affects 2 to 3% of the US population. It is defined by broad criteria, including significantly subaverage intelligence, onset by age 18, and impaired function in a group of adaptive skills. A myriad of genetic and environmental causes have been described, but for approximately half of individuals diagnosed with mental retardation the molecular basis remains unknown. Genomic microarrays, also called array comparative genomic hybridization (array CGH), represent one of several novel technologies that allow the detection of chromosomal abnormalities, such as microdeletions and microduplications, in a rapid, high throughput fashion from genomic DNA samples. In one early application of this technology, genomic microarrays have been used to characterize the extent of chromosomal changes in a group of patients diagnosed with one particular type of disorder that causes mental retardation, such as deletion 1p36 syndrome. In another application, DNA samples from individuals with idiopathic mental retardation have been assayed to scan the entire genome in attempts to identify chromosomal changes. Genomic microarrays offer both a genome-wide perspective of chromosomal aberrations as well as higher resolution (to the level of approximately one megabase) compared to alternative available technologies.
智力迟钝影响着2%至3%的美国人口。其定义依据广泛的标准，包括显著低于平均水平的智力、18岁之前发病以及一组适应性技能方面的功能受损。已经描述了无数的遗传和环境病因，但对于大约一半被诊断为智力迟钝的个体而言，其分子基础仍然未知。基因组微阵列，也称为阵列比较基因组杂交（array CGH），是几种新技术之一，它能够以快速、高通量的方式从基因组DNA样本中检测染色体异常，如微缺失和微重复。在这项技术的一项早期应用中，基因组微阵列已被用于描述一组被诊断患有导致智力迟钝的一种特定类型疾病（如1p36缺失综合征）的患者的染色体变化程度。在另一项应用中，对患有特发性智力迟钝个体的DNA样本进行检测，以扫描整个基因组，试图识别染色体变化。与其他可用技术相比，基因组微阵列既能提供全基因组范围的染色体畸变情况，又具有更高的分辨率（达到大约1兆碱基的水平）。
