2018医学考博英语阅读理解文章精析：自闭症

2018-02-22 09:19:00来源：网络

2018医学考博英语阅读理解文章精析：自闭症

　　2018医学考博英语第四部分阅读理解，此类题目是测试考生通过阅读英文书刊获取信息的能力(包括阅读速度和理解程度)，下面新东方在线考博频道从网络搜集整理了一系列医学考博英语阅读理解文章进行精析，希望对大家提高医学考博英语阅读能力有所帮助。

　　Autism

　　自闭症

　　Why it's not “Rain Woman”

　　为什么它不是 “雨女”

　　Women have fewer cognitive disorders than men do because their bodies are better at ignoring the mutations which cause them

　　与男性相比，患有认知障碍的女性较少，因为她们自身的身体能更好的忽略导致认知障碍的基因突变

　　AUTISM is a strange condition. Sometimes its symptoms of “social blindness” (an inability to read or comprehend the emotions of others) occur alone. This is dubbed high-functioning autism, or Asperger's syndrome. Though their fellow men and women may regard them as a bit odd, high-functioning autists are often successful (sometimes very successful) members of society. On other occasions, though, autism manifests as part of a range of cognitive problems. Then, the condition is debilitating. What is common to those on all parts of the so-called autistic spectrum is that they are more often men than women—so much more often that one school of thought suggests autism is an extreme manifestation of what it means, mentally, to be male. Boys are four times more likely to be diagnosed with autism than girls are. For high-functioning autism, the ratio is seven to one.

　　自闭症是一种奇怪的状态。有时它是由“社会失明”症状(无法阅读或理解他人的情绪)导致的孤独。这被称为高功能自闭症，或亚斯伯格症候群。虽然他们的男性和女性同伴会认为他们有点奇怪，但高功能自闭患者通常是成功的社会人士(有时非常成功)。然而，另一些场合，自闭症表现为一系列认知问题的一部分。那么，条件逐渐衰弱。对于那些所有被称为自闭症患者范围的人来说共同点是男性远多于女性，以至于一个学校认为自闭症意味着一种极端的在心理上表现为一名男性。比起女孩而言，男孩有四倍的可能性被诊断为自闭症。至于高功能自闭症，比率达到 7 比 1。

　　Moreover, what is true of autism is true, to a lesser extent, of a lot of other neurological and cognitive disorders. Attention deficit hyperactivity disorder (ADHD) is diagnosed around three times more often in boys than in girls. “Intellectual disability”, a catch-all term for congenital low IQ, is 30-50% more common in boys, as is epilepsy. In fact, these disorders frequently show up in combination. For instance, children diagnosed with an autistic-spectrum disorder often also receive a diagnosis of ADHD.

　　此外，自闭症的真相，在较小程度上，就是神经病学的认知障碍的真相。被诊断为注意力缺乏症的男大约是女孩的三倍。“智力残疾”，一个全面概括先天性智商低下的术语，在男孩中常见比例多达 30%~50%，癫痫症也是。事实上，这些疾病经常共同出现。例如，被诊断为自闭症谱系障碍的小孩经常也收到 ADHD 的诊断。

　　Autism's precise causes are unclear, but genes are important. Though no mutation which, by itself, causes autism has yet been discovered, well over 100 are known that make someone with them more vulnerable to the condition.

　　导致自闭症的确切原因还不知道，但是基因很重要原因。虽然还没发现是由于它自身的突变导致自闭症，但超过 100 个基因被认为是使某些人在环境影响下更容易受到攻击的对象。

　　Most of these mutations are as common in women as in men, so one explanation for the divergent incidence is that male brains are more vulnerable than female ones to equivalent levels of genetic disruption. This is called the female-protective model. The other broad explanation, social-bias theory, is that the difference is illusory. Girls are being under-diagnosed because of differences either in the ways they are assessed, or in the ways they cope with the condition, rather than because they actually have it less. Some researchers claim, for example, that girls are better able to hide their symptoms.

　　这些突变在男性和女性中是一样普遍的，所以一个对分歧发生率的解释是对于同等的基因毁坏，男性大脑比女性的更容易受伤害。这被称为女性保护模式。另一个广发的解释是社会偏见理论，认为这些不同是虚幻的。这些被诊断不足的女孩，因为她们被评估的方式或对环境的处理不同，而不是他们真的很少有这个症状。例如，一些研究者声称，女孩能更好的隐藏这些症状。

　　To investigate this question, Sebastien Jacquemont of the University Hospital of Lausanne and his colleagues analysed genetic data from two groups of children with cognitive abnormalities. Those in one group, 800 strong, were specifically autistic. Those in the other, 16,000 strong, had a range of problems.

　　为了调查这个问题，洛桑医科大学的医生Sebastien Jacquemont和他的同事分析来自两组患有认识异常症状孩子的基因数据。一组有800人明显确定患有自闭症;另一组是明显有一系列问题。

　　Dr Jacquemont has just published his results in the American Journal of Human Genetics. His crucial finding was that girls in both groups more often had mutations of the sort associated with abnormal neural development than boys did. This was true both for copy-number variants (CNVs, which are variations in the number of copies in a chromosome of particular sections of DNA), and single-nucleotide variants (SNVs, which are alterations to single genetic letters in the DNA message).

　　医生 Jacquemont 刚将他的研究成果发布在美国人类遗传学杂志上。他的关键发现是两组中，女孩比男孩更多有伴随异常神经发展种类的基因突变。这在拷贝数量变异组(CNVs，一组对DNA特定部分的染色体进行复制)和单核苷酸变异组(SNVs，修改 DNA 信使中单独的基因字母)两组中都是对的。

　　On the face of it, this seems compelling evidence for the female-protective model. Since all the children whose data Dr Jacquemont examined had been diagnosed with problems, if the girls had more serious mutations than the boys did, that suggests other aspects of their physiology were covering up the consequences. Females are thus, if this interpretation is correct, better protected from developing symptoms than males are. And, as further confirmation, Dr Jacquemont's findings tally with a study published three years ago, which found that CNVs in autistic girls spanned more genes (and were thus, presumably, more damaging), than those in autistic boys.

　　从表面上看，这似乎是令人信服的女性保护模式证据。因为 Jacquemont 医生检验的所有孩子的数据都被诊断有问题，如果比起男孩，女孩有更严重的突变，那就表面他们生理机能的其他方面掩盖了结果。如果这个解释是正确的，因此女性比男性能在出现的症状中更好的保护自己。而且，作为进一步的确认，Jacquemont 医生的发现与一个三年前发布的研究成果相符，研究发现 CNVs 在自闭症女孩中横跨多个基因(也因此假设更具破坏性)，比患自闭症男孩的多。

　　The counter-argument is that if girls are better at hiding their symptoms, only the more extreme female cases might turn up in the diagnosed groups. If that were true, a greater degree of mutation might be expected in symptomatic girls as a consequence. However, Dr Jacquemont and his colleagues also found that damaging CNVs were more likely to be inherited from a child's mother than from his or her father. They interpret this as further evidence of female-protectedness. Autistic symptoms make people of either sex less likely to become parents. If mothers are the source of the majority of autism-inducing genes in children, it suggests they are less affected by them.

　　相反的观点认为如果女孩能更好的隐藏他们的症状，在被诊断的小组中，只有更极端女性案例会出现。如果这是正确的，那么在女孩症候群中预期有更多程度的突变。然而，Jacquemont 医生和他的同事同样也发现受损的 CNVs 遗传于母亲的可能性大于他或她的父亲。他们解释这进一步证明了女性保护机制。自闭症症状使任何性别的人都不大愿意成为父母。如果母亲是孩子自闭症诱导基因的主要来源，因此建议孩子们能少受到影响母体的影响。

　　None of this, though, explains the exact mechanism that makes boys more susceptible than girls. On this question, too, there are two predominant theories. The first is that males are more sensitive because they have only one X-chromosome. This makes them vulnerable to mutations on that chromosome, because any damaged genes have no twin to cover for them. One cognitive disorder, fragile-X syndrome, is indeed much more common in men for this reason. Dr Jacquemont's study, however, found only a limited role for X-chromosome mutations. That suggests the genetic basis of the difference is distributed across the whole genome.

　　即使没有这个，准确机制也说明男孩比女孩更易受到影响。在这个问题上，也有两个主要的理论。第一个理论认为男性更敏感，因为他们只有一个X染色体。这使对染色体的突变更易受影响，因为任何受损基因都没有双胞胎来掩盖。认知障碍，X 染色体易损综合症，确实因为这个原因在男性中很常见。然而 Jacquemont 医生的研究发现X染色体突变的作用有限。这表明该差异的遗传基础是分布在整个基因组的。

　　The other kind of explanation is anatomical. It is based on brain-imaging studies which suggest differences between the patterns of internal connection in male and female brains. Male brains have stronger local connections, and weaker long-range ones, than do female brains. That is similar to a difference seen between the brains of autistic people and of those who are not. The suggestion here is that the male-type connection pattern is somehow more vulnerable to disruption by the factors which trigger autism and other cognitive problems. Why that should be, however, remains opaque.

　　另一种解释则是解剖学意义上的。它基于男性和女性大脑内部连接模式差异的脑成像研究。男性大脑比起女性而言，有较强的本地连接，较弱的长范围连接。这与是否患有自闭症者大脑的不同相似。这表明男性类型连接模式在某种程度上更加易受因此自闭症的其他认知障碍因素得破坏。然而为什么会这样，仍是未解之谜。