“ 这项研究，首次为自闭症发病率真正的增长原因提供了一些坚实的科学证据。研究做得非常好，对病例特点的分析也极为精细。”耶鲁大学医学院(Yale School of Medicine)儿童研究中心(Child Study Center)主任弗雷德•R•福尔克马尔博士(Fred R. Volkmar) 说，他并没有参与这项研究。

　　“This study provides some of the first solid scientific evidence for a true increase in the condition” of autism, said Dr. Fred R. Volkmar, director of the Child Study Center at the Yale School of Medicine, who was not involved in the research. “It is extremely well done and the sample meticulously characterized.”

　　这项新的调查由冰岛的基因解码公司(DeCode Genetics)带领完成，分析了78组父、母、子的血样中遗传物质。研究集中于那些父母没有精神疾病的迹象，生出的孩子却得了自闭症或精神分裂症的家庭。这种方法使科学家可以分离出那些在父母基因中不存在，却在子女基因中发生了的新突变。

　　The new investigation, led by the Icelandic firm Decode Genetics, analyzed genetic material taken from blood samples of 78 parent-child trios, focusing on families in which parents with no signs of a mental disorder gave birth to a child who developed autism or schizophrenia. This approach allows scientists to isolate brand-new mutations in the genes of the child that were not present in the parents.

　　大多数人有很多这种所谓的“新生突变”，这些突变在母亲受孕时或孕后不久随机发生，大多数是无害的。但最近有研究显示，某些这样的突变会显著增加患上自闭症，或者是精神分裂症的风险。子女新生突变越多，发生某种罕见的致病突变的几率也就越高。

　　Most people have many of these so-called de novo mutations, which occur spontaneously at or near conception, and a majority of them are harmless. But recent studies suggest that there are several such changes that can sharply increase the risk for autism and possibly schizophrenia — and the more a child has, the more likely he or she is by chance to have one of these rare, disabling ones.

　　父亲和母亲双方的遗传差异是不难想见的。精子细胞大约每隔15天就进行一次分裂，但卵细胞相对来说比较稳定。而持续不断的复制不可避免地会导致错误，生活中如此，DNA也是一样。

　　Some difference between the paternal and maternal side is to be expected. Sperm cells divide every 15 days or so, whereas egg cells are relatively stable, and continual copying inevitably leads to errors, in DNA as in life.

　　然而，当研究者排除父方年龄的因素后，他们还是发现，那些患有自闭症或精神分裂症的研究对象和作为对照组的正常冰岛人之间，在遗传风险上没有不同。“考虑到环境因素和人口的多样化，所有额外的风险都可以归因于父亲的年龄，这简直太惊人了。”Decode公司的首席执行官以及该研究的高级作者卡里•斯特凡松 (Kari Stefansson)说道。“同样令人惊讶的是，母亲年龄造成的影响是这么小。”

　　Still, when the researchers removed the effect of paternal age, they found no difference in genetic risk between those who had a diagnosis of autism or schizophrenia and a control group of Icelanders who did not. “It is absolutely stunning that the father’s age accounted for all this added risk, given the possibility of environmental factors and the diversity of the population,” said Dr. Kari Stefansson, the chief executive of Decode and the study’s senior author. “And it’s stunning that so little is contributed by the age of the mother.”