肌萎缩与痴呆的基因根源

时间：2011-09-22 03:35:19

（单词翻译:单击）

Scientists have made an exciting breakthrough in unraveling（解开，阐明） the genetic2 basis of two debilitating3 neurodegenerative disorders4, amyotrophic lateral5 sclerosis (ALS肌萎缩侧索硬化症) and frontotemporal dementia (FTD额颞叶型失智症). Two independent studies, published online by Cell Press in the journal Neuron, identify a new human genetic mutation6 as the most common cause of ALS and FTD identified to date. This mutation explains at least a third of all familial cases of ALS and FTD within the European population. The research provides key insight into ALS and FTD and may pave the way for development of therapeutic7 strategies for these currently incurable8 diseases. ALS, also known as Lou Gehrig's disease, causes destruction of neurons that control voluntary movement. ALS is characterized by a progressive paralysis9 that often leads to death from respiratory failure within a few years of diagnosis10. FTD, the second most common cause of early-onset dementia, is associated with degeneration of the frontal and temporal lobes11 of the brain and leads to a dramatic deterioration12 in personality, language and behavior. There have been suggestions that these two disorders share some underlying13 genetic features.

 
About 10% of ALS cases and about 50% of FTD cases are thought to be inherited, and, although multiple genes14 have been linked with the disorders, much of the genetic risk has remained unexplained. "Each new gene1 implicated15 in the etiology（病因学） of ALS or FTD provides fundamental insights into the cellular16 mechanisms17 underlying neuron degeneration, as well as facilitating disease modeling and the design and testing of targeted therapeutics," explains Dr. Bryan J. Traynor from the National Institutes of Health who is an author of one of the studies. "Identification of new genes that cause ALS or FTD is of great significance."
 
Recent research has linked a region on chromosome18 9, called 9p21, with both ALS and FTD. Dr. Traynor's group performed an exhaustive next generation genetic analysis of this region in patients with 9p21-associated ALS or FTD, including the group of Finnish ALS patients that had previously19 been used to identify the association with 9p21. A second research group, led by Dr. Rosa Rademakers from the Mayo Clinic Jacksonville, performed a similar analysis using a large family with ALS and FTD linked to chromosome 9p21.
 
Both groups discovered a "repeat expansion" within the non-coding region of C9ORF72, a gene whose function is not known. This mutation argues that both ALS and FTD are diseases caused by defects in RNA metabolism20. This idea is in line with other recent work in ALS, FTD and neurodegenerative diseases more broadly stressing RNA-driven disease pathology.
 
The researchers searched for clinical and pathological characteristics associated with the mutation. "Our findings suggest multiple potential disease mechanisms associated with this repeat expansion," says Dr. Rademakers. "For example, we found evidence of a previously described process where the expansion region accumulates inside the neurons as abnormal structures called RNA foci that are likely to promote disease pathogenesis. Further molecular21 studies are needed to explore how these mechanisms contribute to neurodegeneration."
 
Taken together, the findings of both studies suggest that the repeat expansion in C9ORF72 is a major cause of an unprecedented22 proportion of both sporadic23（零星的） and familial FTD and ALS cases. The mutation explains nearly half of all cases in Finland alone and at least a third of all familial FTD and ALS cases in Europeans. Importantly, the mutation was also associated with a number of non-inherited cases of ALS and FTD. "With this discovery we can now explain nearly all of familial ALS disease in Finland, which has the highest incidence of ALS in the world. In the longer term, the identification of the genetic lesion underlying chromosome 9p21-linked ALS and FTD, together with the observed high frequency in these patient populations, makes it an ideal target for drug development aimed at amelioration（改进） of the disease process," concludes Dr. Traynor.

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1 gene WgKxx     
n.遗传因子，基因
参考例句：
  • A single gene may have many effects.单一基因可能具有很多种效应。
  • The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。
2 genetic PgIxp     
adj.遗传的，遗传学的
参考例句：
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
3 debilitating RvIzXw     
a.使衰弱的
参考例句：
  • The debilitating disease made him too weak to work. 这个令他衰弱的病，使他弱到没有办法工作。
  • You may soon leave one debilitating condition or relationship forever. 你即将永远地和这段霉运说拜拜了。
4 disorders 6e49dcafe3638183c823d3aa5b12b010     
n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调
参考例句：
  • Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
  • The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》
5 lateral 83ey7     
adj.侧面的，旁边的
参考例句：
  • An airfoil that controls lateral motion.能够控制横向飞行的机翼。
  • Mr.Dawson walked into the court from a lateral door.道森先生从一个侧面的门走进法庭。
6 mutation t1PyM     
n.变化，变异，转变
参考例句：
  • People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
  • So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。
7 therapeutic sI8zL     
adj.治疗的，起治疗作用的；对身心健康有益的
参考例句：
  • Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
  • When I was sad,music had a therapeutic effect.我悲伤的时候，音乐有治疗效力。
8 incurable incurable     
adj.不能医治的，不能矫正的，无救的；n.不治的病人，无救的人
参考例句：
  • All three babies were born with an incurable heart condition.三个婴儿都有不可治瘉的先天性心脏病。
  • He has an incurable and widespread nepotism.他们有不可救药的，到处蔓延的裙带主义。
9 paralysis pKMxY     
n.麻痹(症)；瘫痪(症)
参考例句：
  • The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。
  • The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。
10 diagnosis GvPxC     
n.诊断，诊断结果，调查分析，判断
参考例句：
  • His symptoms gave no obvious pointer to a possible diagnosis.他的症状无法作出明确的诊断。
  • The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做一次彻底的调查分析。
11 lobes fe8c3178c8180f03dd0fc8ae16f13e3c     
n.耳垂( lobe的名词复数 )；（器官的）叶；肺叶；脑叶
参考例句：
  • The rotor has recesses in its three faces between the lobes. 转子在其凸角之间的三个面上有凹槽。 来自辞典例句
  • The chalazal parts of the endosperm containing free nuclei forms several lobes. 包含游离核的合点端胚乳部分形成几个裂片。 来自辞典例句
12 deterioration yvvxj     
n.退化；恶化；变坏
参考例句：
  • Mental and physical deterioration both occur naturally with age. 随着年龄的增长，心智和体力自然衰退。
  • The car's bodywork was already showing signs of deterioration. 这辆车的车身已经显示出了劣化迹象。
13 underlying 5fyz8c     
adj.在下面的，含蓄的，潜在的
参考例句：
  • The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
  • This word has its underlying meaning.这个单词有它潜在的含义。
14 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
参考例句：
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
15 implicated 8443a53107b44913ed0a3f12cadfa423     
adj.密切关联的；牵涉其中的
参考例句：
  • These groups are very strongly implicated in the violence. 这些组织与这起暴力事件有着极大的关联。 来自《简明英汉词典》
  • Having the stolen goods in his possession implicated him in the robbery. 因藏有赃物使他涉有偷盗的嫌疑。 来自《现代汉英综合大词典》
16 cellular aU1yo     
adj.移动的；细胞的，由细胞组成的
参考例句：
  • She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
  • Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。
17 mechanisms d0db71d70348ef1c49f05f59097917b8     
n.机械( mechanism的名词复数 )；机械装置；[生物学] 机制；机械作用
参考例句：
  • The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
  • He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》
18 chromosome 7rUzX     
n.染色体
参考例句：
  • Chromosome material with exhibits of such behaviour is called heterochromatin.表现这种现象的染色体物质叫做异染色质。
  • A segment of the chromosome may become lost,resulting in a deletion.染色体的一个片段可能会丢失，结果产生染色体的缺失。
19 previously bkzzzC     
adv.以前，先前（地）
参考例句：
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。
20 metabolism 171zC     
n.新陈代谢
参考例句：
  • After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
  • All living matter undergoes a process of metabolism.生物都有新陈代谢。
21 molecular mE9xh     
adj.分子的；克分子的
参考例句：
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。
22 unprecedented 7gSyJ     
adj.无前例的，新奇的
参考例句：
  • The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
  • A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。
23 sporadic PT0zT     
adj.偶尔发生的 [反]regular；分散的
参考例句：
  • The sound of sporadic shooting could still be heard.仍能听见零星的枪声。
  • You know this better than I.I received only sporadic news about it.你们比我更清楚，而我听到的只是零星消息。

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