GENETICS, MORTALITY AND DEMENTIA IN DOWN SYNDROME

唐氏综合症，精神疾病最常见的遗传原因之一 与遗传因素相关的发育迟缓，大约发生在 1.2每1000名活产婴儿中，通常是由不连续的 减数分裂过程中的第21条染色体导致完全三体 基因，尽管非典型形式偶尔会出现。成年人患有 唐氏综合症受益于公共卫生的进步 导致生命戏剧性延长的做法 期望值。然而，唐氏综合症的特征仍然是 在生命后期阶段死亡率增加。原因： 较高的死亡率可能是由于一些 因素，其中两个是阿尔茨海默病风险增加~S 和明显的过早衰老的趋势。老化过程 对唐氏综合症成年人的研究已经超过100年了 由于多年来出现的症状和体征 阿尔茨海默病~S病在人群中。事实上，人类的脑组织 几乎所有35岁至40岁以上的唐氏综合症成年人 显示有明显的淀粉样斑块积聚， 被认为是阿尔茨海默病神经病理学的标志 推测可能是由于基因的三倍复制和过度表达 位于21号染色体上的β-淀粉样前体蛋白。这个 年龄最大的老年人的基因类型和表型特征(即， 65岁及以上)患有唐氏症精神发育迟滞的成年人 综合症将与他们的年轻同龄人进行比较(也包括 唐氏综合症)，以确定相关的遗传风险因素 与存活率和与痴呆相关的认知衰退有关 阿尔茨海默病~S型。我们已经能够辨认出一组100人 唐氏综合症患者年龄在65岁或以上。调查 这一独特的个人主义者群体将使我们能够描述 ~高龄老年唐氏综合征患者的表型及基因鉴定 以及与延长生存期相关的健康状况因素 一方面是成功的老龄化和老年DAT的发展 其他的。

Down syndrome, one of the most common genetic causes of mental retardation associated with genetic factors, occurs in approximately 1.2 per 1000 live births, is typically caused by a nondisjunction of the 21st chromosome during meiosis resulting in a complete trisomy genotype, although atypical forms occur occasionally. Adults with Down syndrome have benefited from the advances in public health practices that have resulted in a dramatic extension in life expectancy. However, Down syndrome is still characterized by increased mortality rates during later stages of life. Causes of higher mortality rates later in life may be due to a number of factors, two of which are an increased risk for Alzheimer~s disease and an apparent tendency toward premature aging. Aging processes among adults with Down syndrome have been of interest for over 100 years because of the occurrence of the signs and symptoms of Alzheimer~s disease in the population. Indeed, brain tissue of virtually all adults with Down syndrome over 35 to 40 years of age displays significant accumulations of amyloid plaques, historically considered to be a hallmark of Alzheimer's disease neuropathology presumably due to the triplication and over expression of the gene for beta-amyloid precursor protein located on chromosome 21. The genotypic and phenotypic characteristics of the "oldest old" (i.e., 65 and older) adult population with mental retardation due to Down syndrome will be compared to those of their younger peers (also with Down syndrome) in order to identify genetic risk factors associated with survival and the cognitive declines associated with dementia of the Alzheimer~s-type. We have been able to identify a group of 100 people with Down syndrome 65 years of age or older. Investigation of this unique group of individualist will allow us to characterize the phenotype of the ~oldest old~ with Down syndrome and identify genetic and health status factors that are associated with extended survival and successful aging on one hand and the development of DAT on the other.