您現(xiàn)在的位置: Language Tips> Audio & Video> Special Speed News  
       
     





     
    Understanding Down syndrome
    [ 2009-09-10 09:17 ]

     

    People with the disorder are living longer and more productive lives than in the past. But they may also face a higher risk of Alzheimer’s disease at an early age.

    This is the VOA Special English Health Report.

    Human genes are normally organized along 46 chromosomes in our cells, 23 from each parent.

    Understanding Down syndrome

    But some people are born with an extra copy of the 21 chromosome. This third copy is a result of a mistake in cell division. The name for this condition is Down syndrome.

    A British doctor named John Langdon Down first described it in the 1860s. An estimated 350 thousand people in the United States have Down syndrome.

    Many babies with Down syndrome have low muscle tone, so they need extra support when they are held. Their heads are smaller than average and they can have unusually shaped ears. Also, their eyes often angle upward.

    People with Down syndrome often have other conditions. These include problems with their heart and with their breathing and hearing. A lot of these conditions, though, are treatable.

    About one in every 100 people with Down syndrome will develop leukemia, a cancer of the blood. But the National Down Syndrome Society says many of these cases are curable as well.

    As a result, people with Down syndrome are living longer. In the early 1980s they lived an average of just 25 years. Today the life expectancy for someone with Down syndrome is 60 years.

    But with that longer life, people with Down syndrome may have an increased risk for Alzheimer's disease at an early age. An estimated 25 percent of those 35 and older show signs of the brain-wasting disease. It slowly destroys memory, thinking and reasoning skills. Alzheimer's is usually not found in the general population until people are over the age of 65.

    Down syndrome is the most common genetic cause of mental retardation. Many people with Down syndrome are mildly to moderately retarded. Many, however, are able to attend regular classes with other students. And later, as adults, many are able to hold jobs and lead independent lives.

    There are tests that can be done to look for Down syndrome during pregnancy.

    The risk of having a baby with Down syndrome increases with the mother's age. The rate is one in every 1200 births at age 25. At 35 it rises to one in 350 births. And at 45 the rate is one in 30.

    And that's the VOA Special English Health Report, written by Caty Weaver. I'm Steve Ember.

    chromosome: a circular strand of DNA in bacteria that contains the hereditary information necessary for cell life 染色體

    leukemia: a malignancy of blood-producing tissues, characterized by proliferating immature white blood cells and infiltration of the spleen, liver, and other organs 白血病

    Related stories:

    New study disputes 'depression dene' finding

    Deferred Happiness Syndrome

    Biomarkers show little help in predicting heart disease

    Obese People Have 'Severe Brain Degeneration'

    (Source: VOA 英語(yǔ)點(diǎn)津編輯)

     

    英語(yǔ)點(diǎn)津版權(quán)說(shuō)明:凡注明來(lái)源為“英語(yǔ)點(diǎn)津:XXX(署名)”的原創(chuàng)作品,除與中國(guó)日?qǐng)?bào)網(wǎng)簽署英語(yǔ)點(diǎn)津內(nèi)容授權(quán)協(xié)議的網(wǎng)站外,其他任何網(wǎng)站或單位未經(jīng)允許不得非法盜鏈、轉(zhuǎn)載和使用,違者必究。如需使用,請(qǐng)與010-84883631聯(lián)系;凡本網(wǎng)注明“來(lái)源:XXX(非英語(yǔ)點(diǎn)津)”的作品,均轉(zhuǎn)載自其它媒體,目的在于傳播更多信息,其他媒體如需轉(zhuǎn)載,請(qǐng)與稿件來(lái)源方聯(lián)系,如產(chǎn)生任何問(wèn)題與本網(wǎng)無(wú)關(guān);本網(wǎng)所發(fā)布的歌曲、電影片段,版權(quán)歸原作者所有,僅供學(xué)習(xí)與研究,如果侵權(quán),請(qǐng)?zhí)峁┌鏅?quán)證明,以便盡快刪除。
    相關(guān)文章 Related Story
     
     
     
    本頻道最新推薦
     
    Rat race 激烈的競(jìng)爭(zhēng)
    聯(lián)合競(jìng)標(biāo) joint bid
    揭秘:米歇爾·奧巴馬如何練就健美雙臂?
    磨洋工 warm-chair attrition
    Manners 文明禮貌
    翻吧推薦
     
    論壇熱貼
     
    經(jīng)典英語(yǔ)口語(yǔ),不得不看(推薦)
    I chocolate you!怎么翻譯?
    請(qǐng)教obama演講里的一句話
     
    曬曬小D機(jī)器人暴強(qiáng)的翻譯
    美國(guó)校園最in俗語(yǔ)大全

     

    无码人妻精品一区二区三18禁| 无码人妻一区二区三区在线视频 | 免费A级毛片无码鲁大师| 熟妇人妻系列av无码一区二区| 国产精品无码永久免费888| 国产成人A亚洲精V品无码 | 人妻少妇精品视中文字幕国语| 日韩精品久久无码人妻中文字幕| 亚洲精品一级无码中文字幕| 亚洲AV永久无码精品一区二区| 日日摸日日碰夜夜爽无码| 熟妇人妻系列av无码一区二区| 熟妇人妻无码中文字幕| 日韩AV无码不卡网站| 国产在线精品无码二区| 性无码一区二区三区在线观看| 免费A级毛片无码A∨免费| 精品久久久久久久中文字幕| 精品久久久久中文字幕日本| 中文字幕乱码免费视频| 精品无码综合一区| 惠民福利中文字幕人妻无码乱精品| 亚洲AV日韩AV永久无码久久| 伊人久久精品无码二区麻豆| 中文字幕亚洲第一在线| 精品久久亚洲中文无码| 中文字幕精品无码久久久久久3D日动漫 | 精品爆乳一区二区三区无码av| 岛国无码av不卡一区二区| 日韩精品无码一区二区视频| 国产资源网中文最新版| 我的小后妈中文翻译 | 日韩精品无码免费专区午夜| 再看日本中文字幕在线观看| 亚洲欧美中文日韩V在线观看| 亚洲国产日韩欧美在线a乱码日本中文字幕高清 | 亚洲VA中文字幕无码一二三区 | 午夜无码A级毛片免费视频| 无码精品人妻一区二区三区漫画| 亚洲AV无码一区二区二三区软件| 亚洲av无码乱码国产精品|