研究人员发现新的心脏性猝死遗传危害因子
文章来源:未知 文章作者:enread 发布时间:2011-07-13 01:43 字体: [ ]  进入论坛
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In a large and comprehensive investigation1 into the underlying2 causes of sudden cardiac death (SCD) – a surreptitious(秘密的) killer3 of hundreds of thousands annually4 in the United States – researchers have discovered a variation in the genome's DNA5 sequence that is linked to a significant increase in a person's risk of SCD. The new finding flags a DNA sequence called the BAZ2B locus6, a region along the genome containing three genes7 previously8 unknown to play any role in cardiac biology, according to a report published online June 30 in PLoS Genetics. Understanding how genetic9 variation in this region plays a role in the risk of SCD could eventually help those at risk take steps to prevent it, the researchers say, although they emphasize that a great deal of follow-up work is required.

"Our analysis suggests that if you have one copy of this variant10, your increased risk is double that of someone who doesn't," says Dan Arking, Ph.D., lead author of the study and an associate professor in the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine. "If you have two copies – having inherited one from each parent – you have almost a fourfold increased risk of SCD."

Statistically12 significant though it is, this variant alone doesn't give scientists the information they need to proceed with a clinically useful test or therapy, Arking says. Scientists first need to figure out which of the three genes in the region is the key player, and determine how that gene's function is compromised – likely by using model organisms to investigate their heart-related biological activity.

To identify the variant, a consortium(联合,合伙) of researchers first combined five separate genome wide association studies to survey each of the 3 billion base pairs in the DNA sequences of 1,283 individuals of European ancestry13 who experienced SCD, and more than 20,000 individuals without SCD. They followed up suggestive findings in an additional 3,119 SCD cases and 11,146 non-SCD control subjects from 11 European ancestry studies to confirm that the BAZ2B locus is associated with SCD.

Collecting enough DNA samples to yield statistical11 power has been a challenge for investigators14 studying SCD, Arking says. One reason is that most individuals who experience it do not have clinical signs that would suggest that they are at high-risk for SCD. In addition, only about 10 percent of people survive their initial sudden death events. (Even if the heart stops beating, a person might be saved if the heart is shocked quickly enough back into normal rhythm. The episode is still considered a sudden death event, even if the person survives, because death would have occurred without intervention15.)

"SCD is a distinct disorder16 that involves an electrical instability in the heart," Arking says. "It's what happens when a 40-year-old guy one minute is feeling great, working out on a treadmill17(跑步机) , and the next minute, without warning, drops dead."

Arking emphasized that based on their analyses, plenty of people are walking around with the BAZ2B variant who don't experience sudden death. SCD is a complex disease, he says, meaning this newly identified risk factor is neither necessary nor sufficient as its cause. The variant is independent of other risk factors for sudden cardiac death, which include diabetes18, heart attack, and a prolonged(延长的) QT interval19, a measure of electrical activity in the heart obtained from a standard electrocardiogram (ECG).

"While we've done a great job of treating coronary disease(冠心病) and reducing the risk of heart attacks, we've made very little progress in reducing the risk of sudden cardiac death," Arking says. "The use of genetics to screen broadly is critical because we don't have other measures that will do a good job of identifying people at risk."



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1 investigation MRKzq     
n.调查,调查研究
参考例句:
  • In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
  • He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。
2 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。
3 killer rpLziK     
n.杀人者,杀人犯,杀手,屠杀者
参考例句:
  • Heart attacks have become Britain's No.1 killer disease.心脏病已成为英国的头号致命疾病。
  • The bulk of the evidence points to him as her killer.大量证据证明是他杀死她的。
4 annually VzYzNO     
adv.一年一次,每年
参考例句:
  • Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
  • They celebrate their wedding anniversary annually.他们每年庆祝一番结婚纪念日。
5 DNA 4u3z1l     
(缩)deoxyribonucleic acid 脱氧核糖核酸
参考例句:
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
6 locus L0zxF     
n.中心
参考例句:
  • Barcelona is the locus of Spanish industry.巴塞罗那是西班牙工业中心。
  • Thereafter,the military remained the locus of real power.自此之后,军方一直掌握着实权。
7 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
8 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。
9 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。
10 variant GfuzRt     
adj.不同的,变异的;n.变体,异体
参考例句:
  • We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段,提供强度适合的晒黑建议。
  • In a variant of this approach,the tests are data- driven.这个方法的一个变种,是数据驱动的测试。
11 statistical bu3wa     
adj.统计的,统计学的
参考例句:
  • He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
  • They're making detailed statistical analysis.他们正在做具体的统计分析。
12 statistically Yuxwa     
ad.根据统计数据来看,从统计学的观点来看
参考例句:
  • The sample of building permits is larger and therefore, statistically satisfying. 建筑许可数的样本比较大,所以统计数据更令人满意。
  • The results of each test would have to be statistically independent. 每次试验的结果在统计上必须是独立的。
13 ancestry BNvzf     
n.祖先,家世
参考例句:
  • Their ancestry settled the land in 1856.他们的祖辈1856年在这块土地上定居下来。
  • He is an American of French ancestry.他是法国血统的美国人。
14 investigators e970f9140785518a87fc81641b7c89f7     
n.调查者,审查者( investigator的名词复数 )
参考例句:
  • This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
  • The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》
15 intervention e5sxZ     
n.介入,干涉,干预
参考例句:
  • The government's intervention in this dispute will not help.政府对这场争论的干预不会起作用。
  • Many people felt he would be hostile to the idea of foreign intervention.许多人觉得他会反对外来干预。
16 disorder Et1x4     
n.紊乱,混乱;骚动,骚乱;疾病,失调
参考例句:
  • When returning back,he discovered the room to be in disorder.回家后,他发现屋子里乱七八糟。
  • It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。
17 treadmill 1pOyz     
n.踏车;单调的工作
参考例句:
  • The treadmill has a heart rate monitor.跑步机上有个脉搏监视器。
  • Drugs remove man from the treadmill of routine.药物可以使人摆脱日常单调的工作带来的疲劳。
18 diabetes uPnzu     
n.糖尿病
参考例句:
  • In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者,医生告诫他们不要吃糖。
  • Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。
19 interval 85kxY     
n.间隔,间距;幕间休息,中场休息
参考例句:
  • The interval between the two trees measures 40 feet.这两棵树的间隔是40英尺。
  • There was a long interval before he anwsered the telephone.隔了好久他才回了电话。
TAG标签: death genetic heart
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