VOA标准英语2010年-Researchers Discover Stuttering Gene

Researchers have discovered a gene¹ linked to stuttering, a speech disorder² that afflicts³ an estimated one million adults worldwide.  Scientists believe the finding raises hope that a drug might someday be developed to treat this disabling condition.

Researchers say the speech impediment appears to stem from a defect in the gene that regulates the way brain cells break down and recycle waste products.  This abnormality interferes⁴ with the brain's ability to process speech.

Stuttering causes sufferers to get stuck repeating or prolonging sounds, syllables⁵ or words that interrupt the normal flow of speech.

Experts say most children who stutter seem to magically outgrow⁶ the disorder.

But for people who continue to stutter into adulthood⁷, researcher Dennis Drayna of the US National Institute on Deafness and Other Communicable Disorders⁸ says stuttering can be profoundly disabling.

"I think in some cases it is hardly even viewed as a legitimate⁹ disorder," said Drayna.  "You know people just dismiss it all the time when in fact it's a clear biological disorder that has very big influences on affected¹⁰ individuals."

Stuttering's cause has long been a mystery, but it has frequently been diagnosed as a psychological problem.  Treatments have included strategies to reduce anxiety and stress, and the use of breathing exercises.

But stuttering tends to run in families, a fact that prompted Drayna and colleagues to search for a genetic¹¹ link. 

They homed in on a single gene, known as GNPTAB, which was defective¹² in 46 members of a large Pakistani family.  The abnormal gene also was found in 77 unrelated Pakistanis with the speech impediment.

In addition, the researchers found the same dysfunctional gene in a group of American and British stutterers.

Drayna says the GNPTAB gene is present in all higher-order animals and contributes to humans' unique ability to communicate.

"We're not the biggest.  We're not the strongest.  We're not the fastest.  We don't have the best senses of vision or hearing.  What it is, is our ability to communicate so we can form groups in communities and do much larger things than we could ever do as individual organisms," he added.  "So when you destroy an individual's ability to communicate, you have really destroyed one of the most important aspects that we have as a species."

In addition to the abnormal GNPTAB gene, Drayna's research team discovered that several other defective genes¹³ associated with GNPTAB were also shared by the stutterers.
These genes are involved in a number of inherited metabolic¹⁴ disorders, including Tay Sachs, a rare, incurable¹⁵ and usually fatal disease that causes the destruction of nerve cells in young children. 

Drayna says therapies to replace enzymes¹⁶ that cause the diseases have been developed to treat half a dozen of these metabolic disorders.  He is hopeful there could eventually be a similar treatment for stuttering.

But in a published commentary on the research, Simon Fisher, a speech and language researcher at the Wellcome Trust Center for Human Genetics at Oxford¹⁷ University cautions that before researchers can develop a drug therapy for stuttering, they will need to learn much more about the precise biochemical mechanism¹⁸ of the disorder.
 
Fisher notes that not every stutterer in the Drayna study had the defective gene, meaning there must be a number of other genes tied to stuttering.

"What we can't say that this is a recessive¹⁹ or a dominant²⁰ form," said Fisher.  "All that we can say is that by carrying this particular variant²¹, you have a greater chance of being a stutterer."

An article on the discovery of a gene associated with stuttering, and the commentary by Simon Fisher, are published this week in the New England Journal of Medicine.

 

1 gene   

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 disorder   

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。

3 afflicts   

使受痛苦，折磨( afflict的名词复数 )

参考例句：

• Level 3-Afflicts a target with the Curse of the Silent. 三级-用静默诅咒折磨一个目标。
• Level 1-Afflicts a target with the Curse of the Silent. 一级-用静默诅咒折磨一个目标。

4 interferes   

vi. 妨碍，冲突，干涉

参考例句：

• The noise interferes with my work. 这噪音妨碍我的工作。
• That interferes with my plan. 那干扰了我的计划。

5 syllables   

n.音节( syllable的名词复数 )

参考例句：

• a word with two syllables 双音节单词
• 'No. But I'll swear it was a name of two syllables.' “想不起。不过我可以发誓，它有两个音节。” 来自英汉文学 - 双城记

6 outgrow   

vt.长大得使…不再适用；成长得不再要

参考例句：

• The little girl will outgrow her fear of pet animals.小女孩慢慢长大后就不会在怕宠物了。
• Children who walk in their sleep usually outgrow the habit.梦游的孩子通常在长大后这个习惯自然消失。

7 adulthood   

n.成年，成人期

参考例句：

• Some infantile actions survive into adulthood.某些婴儿期的行为一直保持到成年期。
• Few people nowadays are able to maintain friendships into adulthood.如今很少有人能将友谊维持到成年。

8 disorders   

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》

9 legitimate   

adj.合法的，合理的，合乎逻辑的；v.使合法

参考例句：

• Sickness is a legitimate reason for asking for leave.生病是请假的一个正当的理由。
• That's a perfectly legitimate fear.怀有这种恐惧完全在情理之中。

10 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

11 genetic   

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。

12 defective   

adj.有毛病的，有问题的，有瑕疵的

参考例句：

• The firm had received bad publicity over a defective product. 该公司因为一件次品而受到媒体攻击。
• If the goods prove defective, the customer has the right to compensation. 如果货品证明有缺陷， 顾客有权索赔。

13 genes   

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

14 metabolic   

adj.新陈代谢的

参考例句：

• Impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。
• A number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。

15 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。

16 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

17 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

18 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

19 recessive   

adj.退行的，逆行的，后退的，隐性的

参考例句：

• Blue eyes are recessive and brown eyes are dominant.蓝眼睛是隐性的；而褐色眼睛是显性的。
• Sickle-cell anaemia is passed on through a recessive gene.镰状细胞贫血通过隐性基因遗传给后代。

20 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。

21 variant   

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。