Narayanan S
Department of Pathology, New York Medical College-Metropolitan Hospital Center, 10029 New York, NY U.S.A.
Indian J Clin Biochem. 1999 Jan;14(1):40-8. doi: 10.1007/BF02869150.
The apo E gene located on chromosome 19 in humans is polymorphic. The three apo E isoforms E2, E3, and E4 are coded by three common alleles of the gene. The amyloid plaques in brains of Alzheimer disease (AD) patients are known to contain apo E. There is an increased prevalence of E4 allele in AD patients. apo E exhibits increased binding to a peptide Aβ deriving from amylold precursor protein. apo E, the risk factor for late AD disease is unable to prevent formation of paired helical filaments which in turn destabilizes neuronal microtubules.A variety of molecular techniques are available for apo E genotyping using DNA amplified by the polymerase chain reaction (PCR). The high guanine to cytosine content of apo E is problematic to the extent that the yield of PCR product and hybridization stringency can be compromised. The specificity of diagnosis of late-onset AD can be improved when results of apo E genotyping are evaluated together with clinical criteria.
人类位于19号染色体上的载脂蛋白E（apo E）基因具有多态性。apo E的三种亚型E2、E3和E4由该基因的三个常见等位基因编码。已知阿尔茨海默病（AD）患者大脑中的淀粉样斑块含有apo E。AD患者中E4等位基因的患病率增加。apo E与源自淀粉样前体蛋白的肽Aβ的结合增加。apo E是晚发性AD疾病的风险因素，无法阻止双螺旋丝的形成，而双螺旋丝反过来会破坏神经元微管的稳定性。使用聚合酶链反应（PCR）扩增的DNA，有多种分子技术可用于apo E基因分型。apo E的鸟嘌呤与胞嘧啶含量高存在问题，因为这可能会影响PCR产物的产量和杂交严谨性。当将apo E基因分型结果与临床标准一起评估时，晚发性AD的诊断特异性可以提高。
