ADM-201 dump PMP dumps pdf SSCP exam materials CBAP exam sample questions

我们是否需要做基因检测? – 译学馆
未登陆,请登陆后再发表信息
最新评论 (0)
播放视频

我们是否需要做基因检测?

What Can You Actually Learn from Your Genome?

Thanks to Skillshare for supporting this episode of SciShow.
感谢Skillshare对本期《科学秀》的大力支持
[音乐]
When it comes to your health, it seems like genetic testing promises a lot.
对于健康来说 基因检测似乎大有可为
And it doesn’t just make promises about big health conditions, either.
不仅可以预测整体健康水平
These tests even give advice about
甚至能根据你的基因
what lifestyle, diet, and level of exercise are best for you
对什么样的生活方式 饮食习惯 锻炼强度最利于你
based on your genes.
给出建议
But generally speaking, it might be worth taking some
但总的来说 对基因检测给出的信息
of that information with some grains of salt.
也许该持保留态度
Because while we have gotten pretty good at reading the human genome,
因为尽管目前人类基因组读取工作顺利
we are not experts at it yet.
但仍属入门级别
And when it comes to our bodies,
并且在破解人体基因这块
our genes aren’t so much an open book,
仍未完全揭开其神秘面纱
as the world’s biggest crossword puzzle.
基因仍是世界上最大的谜题
Your genome is the complete set of DNA hidden inside your cells.
你的基因组是隐藏在细胞内的一套完整的DNA
It consists of about 3 billion base pairs,
它由约30亿个碱基对组成
which are molecular building blocks represented
这些碱基对是由字母A G C T来表示的
by four letters: A, G, C, and T.
分子块组成
For most people, those letters are spread
这些字母遍布在大多数人
across 23 pairs of chromosomes and your mitochondria.
的23对染色体和线粒体之内
And they contain pretty much all of the instructions
它们几乎包含了所有的指令
that make you… you.
让你成为独一无二的你
In the last couple of decades,
在过去几十年
we’ve gotten much better at analyzing those instructions
我们在分析这些指令
and understanding what those strings of letters correspond to.
和理解这些字母所对应的含义方面已经做的好多了
And today, genetic testing can help us solve crimes, discover our ancestors,
今天 基因检测可以帮助我们破案 查找血亲
and make important health decisions.
以及做出重要的健康决定
At least some important health decisions.
至少是一些重要的健康决定
One thing genetic tests are great at,
基因检测的伟大之处在于
is telling us about things caused by one, well-understood variable.
让我们了解那些由一个易于理解的变量引起的疾病
Huntington’s disease, for example,
如亨氏舞蹈症
is a disorder that kills neurons in the brain.
这是一种能杀死大脑神经元的疾病
And it’s caused by a mutation to a single gene
是由一个名为HTT的单基因突变引起的病症
known as HTT, which sits on chromosome four.
此基因位于四号染色体上
In this mutation,
在这种突变中
a section of the gene that normally repeats 10-35 times
通常只重复复制10-35次的基因片段
is instead copied much more,
反而被复制得更多
turning its normally helpful product into toxic fragments.
结果造成基因复制异常形成有毒基因片段
So if that mutation comes up in a test,
所以如果在测试中检测出突变
doctors can pretty confidently say what’s going on.
医生几乎可以肯定会发生什么
This is also true with sickle-cell disease.
镰状细胞病也是如此
That story happens on chromosome 11,
这种突变发生在11号染色体
where a mutation in the gene HBB
其中HBB基因的突变
ultimately causes red blood cells to change shape.
最终导致红细胞改变形状
That can cause anemia and vascular problems.
导致贫血和各种血管问题
And again, the mutation is pretty easy to identify.
再者 这种突变是很容易识别的
There are even some smaller things genetic tests can confidently say,
基因测试还可以明确更加细微的事
like how you’ll respond to certain medications.
比如你会对某些药物的反应
For example, people with a certain variant in the gene VKORC1,
例如 VKORC1基因与血栓形成有关
which is involved in making blood clots,
存在这个基因突变的人
can be especially sensitive to the blood thinner warfarin.
对血液稀释剂华法林特别敏感
Essentially, warfarin works by grabbing onto the VKORC1 enzyme
本质上 华法林的工作原理是抓住VKORC1酶
and blocking it from doing its job.
阻止它发挥作用
But some mutations can make a person produce less of this enzyme than normal.
但有些突变会使人产生的这种酶比正常人少
So a typical dose of warfarin becomes an overdose,
所以典型的华法林剂量会变成过量
putting the patient at risk of abnormal bleeding.
使病人面临异常出血的危险
There are also other mutations that make it harder
还有其他的变异
for warfarin to bind to this enzyme,
使得华法林难于结合此酶
meaning those patients might be underdosed by a typical prescription.
也就是说正常药量对于这些人来说剂量不够
So a doctor can use a genetic test
所以医生可以用基因测试
to figure out what dose to give them
找出该给他们多少剂量
or if this drug is even worth trying.
或者判断这种药是否值得一试
The key, though, is that each of these examples is caused
但关键是 这些示例中的每一个都是由
by a specific mutation in a well-known gene.
一个已发现基因的特定突变引起
That means a genetic test can be fairly accurate and pretty useful,
这意味着基因测试准确 有用
because we know exactly what we’re looking for and what it does.
因为我们知道我们在找什么 它是干什么的
But when you move beyond these cases,
但当你偏离这些情况时
the situation gets a lot more complicated.
情况变得复杂多了
Because for most things, there isn’t just one gene to blame.
因为在大多数情况下 元凶不止一个基因
Instead, there can be hundreds or thousands of them.
相反 可能是几百或数千个基因
Let’s take something simple, like height.
让我们举个简单的例子 譬如身高
Tall parents tend to have tall children, right?
高个父母往往孩子也个高 对吧
That’s something we’ve noticed for generations.
这是我们几代人都注意到的
But as much as we’ve looked,
但正如我们所看到的
there doesn’t seem to be a single ‘height gene’.
似乎没有单独的“身高基因”
Instead, one study from 2014 found almost 700 variants
相反 2014年的一项研究发现我们的基因组里
and more than 400 locations in our genome that could all play a part in height,
有近700个变异和400多处基因定位都会影响身高
usually only about a millimeter each, according to one of the authors.
其中一位作者称 通常情况下每处仅会影响一毫米
Later on, some of those same authors did find a few mutations that had bigger effects,
后来他们确实发现有一些小突变能够产生大的影响
but it was still maybe only a couple of centimeters at most.
但最多也就可能影响几厘米
The reason so many genes affect height is that,
有如此多基因影响身高的原因在于
well, a lot of things go into determining how tall someone is,
诸多因素决定了一个人的身高
like how long their leg bones are,
比如腿骨多长
or how much growth hormone their body makes.
或者分泌多少生长激素
And each of those little additions may come
每一个细微的改变中都可能带有
with its own gene or suite of genes.
自己的基因或者配套的基因组
But even if we could perfectly calculate all those effects,
但是即使我们可以完美地计算所有的这些影响
we still might not be able to really predict how tall someone will become.
我们仍不可能真正预测到某个人能长多高
That’s because, as far as we can tell,
因为根据目前的研究
genes only make up about 60-80% of someone’s height.
基因对身高的影响只占6-8成
The other 20 % -40 % comes down to a person’s environment and life history,
其余2-4成的因素取决于生活环境和习惯
like their nutrition.
比如营养
This is a really common example,
这个例子很普通
but the general principles are true for all kinds of things,
但这个原则适用于各种事物
including more serious conditions.
包括更严重的情况
A big one being cancer.
其中一种严重的情况就是癌症
Genetic tests can identify
基因检测能识别出
if someone has inherited a rare gene variant that can increase their risk of cancer,
某人是否遗传了会增加癌症风险的罕见基因变异
including BRCA1 and 2, which are associated with breast and ovarian cancer.
包括与乳腺癌和卵巢癌相关的BRCA1和2的基因
But since this disease doesn’t just have one associated mutation,
但由于这种疾病不仅仅有一个相关的突变
there’s no guarantee that someone will develop it even if their BRCA1 gene is mutated.
即便BRCA1基因发生突变 也不能确定这人就一定会得癌
There are also plenty of other things at work,
也有许多其他因素在起作用
including other genes and environmental factors
包括其他基因和环境因素
and also random chance.
也有随机因素
The same is true for something like type-2 diabetes, or obesity.
二型糖尿病或肥胖症也是如此
In 2018, a cardiologist speaking to NPR noted that
2018年有心脏专家在NPR指出
the genes only account for about 5-10 % of the risk associated with diet-related conditions.
只有5−10成与饮食状况相关的患病风险归因于基因
The rest comes down to behavior and diet.
其余归咎于行为和饮食
In other words, for most conditions, your DNA is not your destiny.
换句话说 在大多数情况下 你的DNA决定不了你的命运
Genetic testing is still useful, though,
但基因检测仍有其意义
because it can help someone know to be vigilant or take precautions,
因为它可以帮助人们提高警惕或采取预防措施
or it could help doctors plan treatments for them.
或者帮助医生为病人制定治疗计划
And really, it only gets more complicated from there,
从这个层面开始变得复杂化
especially once you jump into the realm of mental health or lifestyle choices.
特别是涉及精神健康或者生活方式的选择
Just look at major depression.
比如重度抑郁症
We know that it can run in families,
我们知道它可以遗传
which suggests it has something to do with a person’s genetics.
这表明它与基因有某种联系
And we’ve even found genes that appear to be linked to it.
我们甚至发现与它相呼应的基因
But,if you thought 700 variants for height was a high number,
但如果你认为与身高相关的变异有700个就算多了
brace yourself.
就太天真了
Because for depression, there are literally thousands of genes or gene variants involved.
因为就抑郁而言 有数以千计的基因或者基因变异跟它有关
One 2014 review estimated that as many as one
2014年的一篇综述估计
in every five genes expressed in the brain
在大脑中每五个基因表达中就有一个
might play a role in major depression.
可能在重度抑郁中扮演重要角色
And even then, the estimated heritability was less than 40%.
即使在那时 对遗传率的预估也低于40%
That means more than half of a person’s risk of experiencing depression
这意味着 一个人患抑郁症的风险有一半以上
might come down to things totally unrelated to their genetics.
与他们的基因完全无关
So sure, there are some conditions genetic tests can confidently identify.
当然 基因测试确能识别一些疾病
But in the vast majority of cases,
但在绝大多数情况下
deciphering which genes link to which conditions
破解哪些基因与哪些疾病相关
and how strongly is very difficult.
以及确定相关性的强弱是非常困难的
And actually, this applies to doing research on these traits, too.
这实际也适用于特征性研究
Because while the number of possible variants is definitely a reason understanding a genome is so hard,
因为尽管可能出现的变异数 确实是理解基因组如此困难的原因
it’s not the only reason.
但还存在其他困难
Sometimes, it’s just hard to figure out what all those letters mean.
有时候就连解释这些字母都很难
Say you test a thousand people with a certain condition and find one mutation that really sticks out.
假设你做了千人实验 找出了导致他们同样问题的一个变异
But then a different scientist wants to replicate your study with another group, which,
此时有另一科学家想在另一组人群上复制你的研究
admittedly, is always a good idea.
不可否认 这总是个好主意
How can that researcher be sure their group
但研究者如何能确定他们的样本人群
had the same life history as yours?
跟你的有同样的生活习惯呢?
Or that there’s not another, unknown gene that could influence the results.
或者谁又知道有没有其他未知的基因影响结果呢?
Also, what if the condition you’re studying is actually multiple conditions that look similar?
再者如果你研究的表征实际上是多个看起来类似的情况呢?
How do you control for that?
你如何去控制这些?
To make things even harder,
更困难的是
these studies often need a ton of samples,
这些研究通常需要大量的样本
which can be hard to obtain for rare conditions.
而罕见案例的获取是十分困难的
Like that height study needed data
比如关于身高的研究数据
from more than a quarter of a million people.
需要从超过25万人中获取
And the follow-up used DNA from 700,000 people.
而跟进研究用到了70万人的DNA
All of this can make answering even basic questions about our genes and our bodies complicated.
这一切使得解答基因和身体的基本问题都变得相当复杂
Nevertheless, we’ve made a ton of advancement in the last few years,
话说回来 在过去几年我们已取得了大量进展
which really makes you realize how impressive research is these days.
研究的进度刷新你的认知
According to the National Institutes of Health in the U.S.,
根据美国国立卫生研究院的研究
there’s testing available for over 2000 rare and common conditions.
有超过2000种罕见和常见疾病的测试可供使用
We can also use genetic testing to help plan cancer treatments
基因测试也可用于帮助制定癌症治疗计划
or tell if we’re silent carriers for any serious conditions.
帮助我们确定重大病情的隐性携带者
It’s even commonplace to gene test newborn babies,
对新生儿的基因测试也已经司空见惯了
just in case they have a condition that requires immediate care.
以防他们有需要立即治疗的情况
But as genetic testing becomes more common,
但随着基因测试越来越普遍
it’s also become more important to make sure
确保人们理解基因检测能做什么和不能做什么
people understand what it can and can’t do.
也变得越来越重要了
Because while it is powerful, there are plenty of limitations.
因为即使它很有用 仍然存在许多局限性
Also, if you are considering genetic testing,
还有 如果你正在考虑基因测试
there is one important thing worth noting:
有一点你需要注意:
Even if they can all be helpful, not all tests are created equal.
即使基因测试都有用 也不是说所有测试都一样
There are actually a lot
实际上有许多
of different ways to test a person’s genes.
不同的方法可以测试人类的基因
For example, some tests look for what are called single nucleotide polymorphisms,
比如 某些测试寻找的是单个多形态核苷酸
also called SNPs.
也被称为SNPs
These are places where a single letter of DNA can vary from person to person.
这就是DNA的单个字母在人与人间的不同之处
So some might have a G, and another person might have a T.
有些人可能是G 其他人可能是T
Many direct-to-consumer tests work by,
许多面向普通消费者的测试都基于此
essentially,scanning your DNA for known, potentially dangerous SNPs.
本质上就是扫描你DNA上已知的危险SNPs
But while that might help catch the most important cases,
但尽管这有助于检查出重大病情
these kinds of tests might also ignore less important or less-studied ones.
这些测试也可能忽视那些不那么重要或者研究较浅的案例
Also, while SNPs are some of the most common mutations in our genome,
此外尽管SNPs体现了基因组中最常见的变异
there are other ones, too.
但还存在其他变异
So a test that is only looking for SNPs
因此 单纯查找SNPs的测试
might miss duplicated, deleted, or shifted genes
可能忽略已复制 缺失 或者转移过的基因
that another test might catch.
而另一项测试则能检测出来
That’s not necessarily a flaw,
这不完全算一个缺陷
since the test is working as designed.
因为原本的设计就是这样
But especially if you have a family history of disease,
但尤其对于有家族病史的人
it might be worth keeping
应该时刻保持注意
in mind or talking with a doctor to get the test that’s right for you.
或者与医生沟通来选择适合你的测试
Studying genetics can sometimes seem overwhelming,
研究遗传学有时显得格外复杂
because there are just so many pieces involved.
因为它涉及到方方面面
But by breaking it down into small parts,
但通过将其肢解
you can usually figure out something.
你就能明白一些
And the same is true for learning any new skill.
这个和学习其他其他新技能一样
Like, if you want to start a YouTube channel,
比如你想创建一个油管频道
there’s a long list of things you’ll need to figure out,
你需要学会的东西很多
from your name to your camera to your intro music.
从确定名称到摄像到开场音乐
But if you take it one step at a time,
但如果你一步步来
it will probably be a lot less stressful.
压力就会小很多
And that’s where Skillshare can help you out.
Skillshare可以帮你
They have a bunch of video-related classes,
这有一大堆视频课程
including one called DIY Cinematography,
包括《DIY拍电影》
taught by filmmaker Ryan Booth.
老师是电影制作人布瑞恩
And he goes over your basic vocab and tools,
他将带你学习基础词汇和各种工具
along with things like how you can make the most of your location.
以及如何充分利用你现有的资源等
Skillshare has more than 25,000 classes besides this one,
而且Skillshare有超2万5千多课程
and if you are a premium member,
如果你是高级会员
you can get unlimited access to all of them. Also,
你就能随意观看所有课程
an annual subscription fee is less than $ 10 a month,
年费会员算下来每月只要不到10美元
which is a pretty good deal.
非常划算
So whether you want to pick up new skills for school,
所以无论你是为了学业 职业
for your career, or even your own YouTube channel,
或是油管频道学习新技能
Skillshare has you covered.
Skillshare都有你所想
Also, the first 500 SciShow subscribers to use the link
而且前500个通过简介里的链接来订阅SciShow
in the description will get a 2-month free trial.
可以免费试用两个月
So check it out,
快来看看吧
and let us know if you found any classes that you really liked.
如果您发现了喜欢的课程 请告知我们

发表评论

译制信息
视频概述

什么是基因检测?我们是否应该做基因检测?本视频将为你解答。

听录译者

收集自网络

翻译译者

狗熊绣花

审核员

审核员XY

视频来源

https://www.youtube.com/watch?v=gL5XOWm3l7c

相关推荐