Gene Therapy Delivers Treatment Directly to Brain

Gene¹ Therapy Delivers Treatment Directly to Brain

When Rylae-Ann Poulin was 1 year old, she did not crawl or make noises like other kids her age. A rare genetic² disease prevented her from even lifting her head. Her parents took turns holding her all night to ease her breathing and help her sleep peacefully.

But months later, doctors in Taiwan treated the young patient's brain directly, attacking the disease with genetic medicine. Now the 4-year-old is walking, running, swimming, reading and riding horses.

Rylae-Ann lives with her family in Bangkok, Thailand. She was accepted into a medical trial for a new method of gene therapy. Experts say the treatment holds great promise for treating several brain diseases.

The method was approved in Europe and the United Kingdom for a condition called AADC deficiency. The disorder³ damages communication systems among nervous system cells.

American drug company PTC Therapeutics plans to seek U.S. approval for the treatment this year.

The National Institutes of Health (NIH) says there are about 30 studies underway in the United States right now to test gene therapy to the brain. The studies target a number of diseases.

Dr. Krystof Bankiewicz at Ohio State University leads one such study on AADC deficiency. Others test treatments for brain diseases like Alzheimer's, Parkinson's and Huntington's.

Difficulties remain, especially with diseases caused by more than a single gene. But scientists say evidence is growing in support of gene therapy to the brain.

"There's a lot of exciting times ahead of us," said Bankiewicz, a brain surgeon. "We're seeing some breakthroughs."

The most amazing of those breakthroughs involve Rylae-Ann's disease. It is caused by changes in a gene needed for an enzyme⁴ that helps make neurotransmitters, the body's chemical messengers. The one-time treatment provides a working version of the gene.

At around 3 months old, Rylae-Ann began having what her parents thought were seizures⁵. Fluid sometimes got into her lungs after she ate, a condition that required hospital treatment. Doctors thought she might have epilepsy or cerebral⁶ palsy, more common brain diseases.

Later, her parents found a doctor who correctly identified Rylae-Ann's condition. Her parents entered her into a gene therapy trial in Taiwan. The treatment requires doctors to operate directly on the brain. The doctors injected the genetic material using an extremely narrow tube.

"It gets put into the brain cells and then the brain cells make the (neurotransmitter) dopamine," said Stuart Peltz, leader of PTC Therapeutics.

Company officials said all patients in their trials showed movement and thinking improvements. Some of them, Peltz said, could stand and walk and continue getting better over time.

Bankiewicz of Ohio State University also reported success in his NIH-financed study. He said all 40 or so patients involved saw big improvements.

Barriers to widespread use

Scientists say there are difficulties to face before this treatment becomes common for more brain diseases.

For example, the timing⁷ of treatment is an issue. Generally, earlier in life is better because diseases can cause more problems over the years. Also, more complex disorders⁸ like Alzheimer's are harder to treat with gene therapy.

A more basic barrier is cost. The price of gene therapies, paid for mostly by insurers and governments, can be in the millions. The one-time PTC therapy costs more than $3 million in Europe, for example.

But drugmakers say they want people to get the treatments they need. And researchers are hopeful they can clear the remaining scientific barriers to this method.

"So I would say gene therapy can be leveraged¹⁰ for many sorts of brain diseases and disorders," said Ryan Gilbert. He is a biomedical engineer at New York's Rensselaer Polytechnic¹¹ Institute. "In the future, you're going to see more technology doing these kinds of things," he added.

Words in This Story

breakthrough — n. a sudden increase in knowledge, understanding, etc.

dopamine — n. a compound present in the body as a neurotransmitter

insurer — n. a company that provides insurance

leverage⁹ — v. influence or power used to achieve a desired result

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 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。

3 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。

4 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

5 seizures   

n.起获( seizure的名词复数 )；没收；充公；起获的赃物

参考例句：

• Seizures of illicit drugs have increased by 30% this year. 今年违禁药品的扣押增长了30%。 来自《简明英汉词典》
• Other causes of unconsciousness predisposing to aspiration lung abscess are convulsive seizures. 造成吸入性肺脓肿昏迷的其他原因，有惊厥发作。 来自辞典例句

6 cerebral   

adj.脑的，大脑的；有智力的，理智型的

参考例句：

• Your left cerebral hemisphere controls the right-hand side of your body.你的左半脑控制身体的右半身。
• He is a precise,methodical,cerebral man who carefully chooses his words.他是一个一丝不苟、有条理和理智的人，措辞谨慎。

7 timing   

n.时间安排，时间选择

参考例句：

• The timing of the meeting is not convenient.会议的时间安排不合适。
• The timing of our statement is very opportune.我们发表声明选择的时机很恰当。

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 leverage   

n.力量，影响；杠杆作用，杠杆的力量

参考例句：

• We'll have to use leverage to move this huge rock.我们不得不借助杠杆之力来移动这块巨石。
• He failed in the project because he could gain no leverage. 因为他没有影响力，他的计划失败了。

10 leveraged   

促使…改变( leverage的过去式和过去分词 )； [美国英语]杠杆式投机，（使）举债经营，（使）利用贷款进行投机

参考例句：

• Chrysler has traditionally been a highly leveraged company. 克莱斯勒一向是一家周转十分灵活的公司。
• Leveraged recaps have become popular for a number of reasons. 杠杆资本重组的大行其道有好几个原因。

11 polytechnic   

adj.各种工艺的，综合技术的；n.工艺(专科)学校；理工(专科)学校

参考例句：

• She was trained as a teacher at Manchester Polytechnic.她在曼彻斯特工艺专科学校就读，准备毕业后做老师。
• When he was 17,Einstein entered the Polytechnic Zurich,Switzerland,where he studied mathematics and physics.17岁时，爱因斯坦进入了瑞士苏黎士的专科学院，学习数学和物理学。