http://www.nature.com/news/2010/101122/ ... 0.625.html
Published online 22 November 2010 | Nature | doi:10.1038/news.2010.625The birthday candles in your veins
DNA artefacts from white blood cells offer forensic clues to a person's age.
A drop of blood can provide a rough estimate of a person's age, helping forensic investigators to draw physical profiles of suspects and victims who leave few other traces behind.
Conventional forensic DNA analysis matches samples gathered from crime scenes and compares them with those of people identified in an investigation or in a database. Increasingly, however, investigators are building physical profiles of individuals on the basis of their DNA alone. For instance, six genetic markers can indicate whether a person has blue or brown eyes1.
In a paper published online today in Current Biology2, researchers based in the Netherlands report a genetic signature for a person's age — to within a decade or so — in a type of white blood cell known as a T cell. Other means of accurately determining a person's age rely on skeletal remains. But, in "most cases you don't have bones or teeth you simply have stains", says Manfred Kayser, a geneticist at Erasmus University Medical Center in Rotterdam, the Netherlands, and a co-author on the paper.