Podlisny M B, Lee G, Selkoe D J
Department of Neurology, Harvard Medical School, Boston, MA 02115.
Science. 1987 Oct 30;238(4827):669-71. doi: 10.1126/science.2960019.
The progressive deposition in the human brain of amyloid filaments composed of the amyloid beta protein is a principal feature of Alzheimer's disease (AD). Densitometric analysis of Southern blots probed with a complementary DNA for the amyloid protein has been carried out to determine the relative dosage of this gene in genomic DNA of 14 patients with AD, 12 aged normal subjects, and 10 patients with trisomy 21 (Down syndrome). Whereas patients in the last group showed the expected 1.5-fold increase in dosage of this gene, none of the patients with AD had a gene dosage higher than that of the normal controls. These results do not support the hypothesis that the genetic defect in AD involves duplication of a segment of chromosome 21 containing the amyloid gene. Alternative mechanisms for the brain-specific increase in amyloid protein deposition in AD should be considered.
由β-淀粉样蛋白组成的淀粉样细丝在人脑中的进行性沉积是阿尔茨海默病（AD）的主要特征。已进行了用淀粉样蛋白互补DNA探测的Southern印迹光密度分析，以确定该基因在14例AD患者、12例老年正常受试者和10例21三体综合征（唐氏综合征）患者基因组DNA中的相对剂量。最后一组患者该基因剂量预期增加了1.5倍，而AD患者中没有一个的基因剂量高于正常对照。这些结果不支持AD的遗传缺陷涉及含有淀粉样基因的21号染色体片段重复的假说。应考虑AD中淀粉样蛋白沉积脑特异性增加的其他机制。
