科技日报---当DNA撒谎时：法医学中隐藏的缺陷
2025-01-09 13:29阅读：
关键词：DNA、基因相似群体、低遗传多样性、假阳性
题记：
DNA也有不可信的时候，这对于刑侦工作有些挑战。看来，任何技术都不是完美无缺的，面临这样的挑战，是否要寻找新的突破口来解决刑侦工作遇到的问题呢？！
When DNA Lies: The Hidden Flaws in Forensic
Science
当DNA撒谎时：法医学中隐藏的缺陷
A University of Oregon study reveals challenges in
forensic DNA mixture analysis, particularly for groups with low
genetic diversity, which are at higher risk for false positive
results in criminal investigations.
俄勒冈大学的一项研究揭示了法医
DNA混合分析的挑战，特别是对于遗传多样性低的群体，他们在刑事调查中获得假阳性结果的风险更高。
Researchers reveal the complexities and limitations of
forensic DNA analysis, especially when dealing with DNA mixtures
from genetically similar groups.
研究人员揭示了法医DNA分析的复杂性和局限性，特别是在处理来自基因相似群体的DNA混合物时。
The study, using simulated genetic mixtures, indicates
that such groups are more prone to false positives, raising ethical
concerns about the use of DNA evidence in criminal
investigations.
这项使用模拟遗传混合物的研究表明，这些群体更容易出现假阳性，这引发了人们对在刑事调查中使用DNA证据的伦理担忧。
Forensic DNA Challenges
A swab of DNA from a door handle or drinking glass isn’t
always a foolproof way to determine who committed a
crime.
法医DNA挑战
从门把手或饮水杯上采集DNA样本并不总是确定谁犯罪的万无一失的方法。
Researchers at the University of Oregon, writing in the
journal iScience, found that forensic DNA analysis becomes less
reliable when dealing with DNA mixtures from groups with low
genetic diversity. In such cases, the technique is more likely to
wrongly identify an innocent person as being present at the scene —
a mistake with potentially life-altering
consequences.
俄勒冈大学的研究人员在《iScience》杂志上写道，当处理来自低遗传多样性群体的DNA混合物时，法医DNA分析变得不那么可靠。在这种情况下，该技术更有可能错误地将无辜者识别为现场人员，这一错误可能会改变生命。
Advances and Limitations in DNA Analysis
Techniques
Modern DNA analysis is highly sensitive, capable of
detecting even tiny traces of genetic material left behind by skin
cells. This allows forensic scientists to link DNA to specific
individuals. However, this sensitivity comes with a challenge: DNA
samples often contain genetic material from multiple people, such
as everyone who recently touched the same door handle. This can
make it harder to pinpoint whose DNA is relevant to the
investigation.
DNA分析技术的进展与局限
现代DNA分析非常灵敏，能够检测到皮肤细胞留下的微小遗传物质痕迹。这使得法医科学家能够将DNA与特定个体联系起来。然而，这种敏感性也带来了挑战：DNA样本通常包含来自多个人的遗传物质，比如最近接触过同一个门把手的每个人。这可能会使确定谁的DNA与调查有关变得更加困难。
By looking at the variation of certain genetic markers in
the sample and comparing it to the suspect’s DNA, researchers can
quantify the strength of the evidence linking a particular person
to the mixture.
通过观察样本中某些遗传标记的变异并将其与嫌疑人的DNA进行比较，研究人员可以量化将特定人与混合物联系起来的证据的强度。
The Impact of Genetic Ancestry on DNA Analysis
Accuracy
DNA mixture analysis can be powerful when used correctly,
but it’s crucial to understand the technique’s limitations and when
it should be wielded with particular caution, said Rori Rohlfs, a
data scientist at the University of Oregon who led the work
alongside a group of undergraduate researchers from San Francisco
State University.
遗传谱系对DNA分析准确性的影响
俄勒冈大学的数据科学家罗里·罗尔夫（Rori
Rohlfs）与旧金山州立大学的一组本科生研究人员一起领导了这项工作，他说，正确使用DNA混合物分析可能会很强大，但了解这项技术的局限性以及何时应该特别谨慎地使用它至关重要。
Rohlfs and her team wanted to see how the accuracy of that
approach is affected by people’s genetic ancestry. They combed
through previously published genetic databases to get data on the
frequency of certain genetic variants for groups of people with
different genetic ancestry. Then, they used forensic analysis
software to simulate profiles of individuals, as well as mixtures
of DNA representing groups of people from different genetic
backgrounds.
Rohlfs和她的团队想看看这种方法的准确性是如何受到人们遗传血统的影响的。他们梳理了之前发表的遗传数据库，以获取具有不同遗传血统的人群中某些遗传变异频率的数据。然后，他们使用法医分析软件来模拟个体的特征，以及代表不同遗传背景人群的DNA混合物。
In mixtures with lower genetic diversity, the team found
the technique was more likely to yield a false positive; that is,
to incorrectly link someone to the mixture who wasn’t actually
involved. And the problem worsened when the mixture contained DNA
from more people.
在遗传多样性较低的混合物中，研究小组发现该技术更有可能产生假阳性；也就是说，错误地将某人与实际上没有参与的混合物联系起来。当混合物中含有更多人的DNA时，问题变得更加严重。
“The accuracy of DNA mixture analysis really varies by
genetic ancestry,” Rohlfs said. “Groups with less diverse genetic
variants are going to have higher false inclusion rates for DNA
mixture analysis, and this gets worse when you have more
contributors.”
-----Ethical Considerations in Genetic
Research
“DNA混合物分析的准确性确实因遗传血统而异，”Rohlfs说。“遗传变异多样性较低的群体在DNA混合分析中的错误包含率会更高，当贡献者更多时，情况会变得更糟。”
-----遗传学研究中的伦理考量
The study involved simulated genetic mixtures generated
from complex datasets, so the researchers can’t specifically say
that the technique is less accurate for certain genetic ancestry
groups. Plus, traditional race and ethnicity labels are often
overly broad and don’t always accurately map to genetic ancestry,
Rohlfs said.
该研究涉及从复杂数据集生成的模拟遗传混合物，因此研究人员不能具体说该技术对某些遗传祖先群体的准确性较低。此外，Rohlfs说，传统的种族和民族标签往往过于宽泛，并不总是准确地映射到遗传血统。
However, some examples of groups that might have less
genetic diversity include certain Indigenous, Latine or Pacific
Islander groups.
The research also reflects the challenges of doing ethical
genetic research, Rohlfs said. Many of the studies her team looked
to for data did not necessarily practice informed consent when
collecting people’s DNA, sometimes getting samples from
incarcerated people. The research team opted to only include data
from subjects where informed consent could be verified, somewhat
limiting their data pool.
然而，一些可能遗传多样性较低的群体包括某些土著、拉丁裔或太平洋岛民群体。
Rohlfs说，这项研究也反映了进行伦理遗传研究的挑战。她的团队寻找数据的许多研究在收集人们的DNA时不一定实行知情同意，有时甚至从被监禁的人身上获取样本。研究小组选择只包括可以验证知情同意的受试者的数据，这在一定程度上限制了他们的数据池。
Rohlfs is currently building up her lab at the UO, and she
hopes to continue investigating the accuracy of other emerging
forensic DNA analysis techniques.
Rohlfs目前正在俄勒冈大学建立她的实验室，她希望继续研究其他新兴法医DNA分析技术的准确性。
