据国外媒体报道，英国科学家研究显示，平均每个人的DNA中含有约400个遗传缺陷。其中大多数是不影响健康的“沉默”突变，但是当遗传给后代的时候或许就会造成一定的问题。遗传学家表示，有些突变也会在晚年的时候造成癌症或心血管疾病。
平均每个人DNA中含有约400个遗传突变缺陷，其中大多数是不影响健康的“沉默”突变。
证据来自于1000人基因组工程，这项工程旨在描绘正常人之间的基因差异，从微小的DNA变化到巨大的DNA突变。
在这项工程中，科学家对来自欧洲、美国和东亚的1000名健康人进行了全序列基因组测序，以便找出人与人之间产生差异的原因，有助于与遗传相关疾病的研究。
这项新研究发表在了《美国人类遗传学》杂志上，其中精细对比了179名参与者的基因组序列，储存在了英国卡迪夫大学开发的人类基因突变数据库里（Database of human mutations）。
主导该研究的英国剑桥大学Chris Tyler-Smith博士说：“携带致病基因突变的个人通常没有明显的表现，但对于一个人群来说，基因突变对整体的健康有影响。”
来自英国卡迪夫大学的David Cooper教授说：“这项研究洞悉了人与人之间不同的遗传学原因，通常表现有不同的专长和能力，也表现在对不同疾病的易感倾倾向。人类的基因组并没有完美测定，其中深藏有众多的遗传缺陷。”
Deleterious- and Disease-Allele Prevalence in Healthy Individuals: Insights from Current Predictions, Mutation Databases, and Population-Scale Resequencing
Yali Xue, Yuan Chen, Qasim Ayub, Ni Huang, Edward V. Ball, Matthew Mort, Andrew D. Phillip, Katy Shaw, Peter D. Stenson, David N. Cooper, Chris Tyler-Smith, and the 1000 Genomes Project Consortium
We have assessed the numbers of potentially deleterious variants in the genomes of apparently healthy humans by using (1) low-coverage whole-genome sequence data from 179 individuals in the 1000 Genomes Pilot Project and (2) current predictions and databases of deleterious variants. Each individual carried 281–515 missense substitutions, 40–85 of which were homozygous, predicted to be highly damaging. They also carried 40–110 variants classified by the Human Gene Mutation Database (HGMD) as disease-causing mutations (DMs), 3–24 variants in the homozygous state, and many polymorphisms putatively associated with disease. Whereas many of these DMs are likely to represent disease-allele-annotation errors, between 0 and 8 DMs (0–1 homozygous) per individual are predicted to be highly damaging, and some of them provide information of medical relevance. These analyses emphasize the need for improved annotation of disease alleles both in mutation databases and in the primary literature; some HGMD mutation data have been recategorized on the basis of the present findings, an iterative process that is both necessary and ongoing. Our estimates of deleterious-allele numbers are likely to be subject to both overcounting and undercounting. However, our current best mean estimates of ∼400 damaging variants and ∼2 bona fide disease mutations per individual are likely to increase rather than decrease as sequencing studies ascertain rare variants more effectively and as additional disease alleles are discovered.
文献链接：https://www.cell.com/AJHG/abstract/S0002-9297(12)00538-1
