Predicting Physical Appearance From DNA
News Feb 06, 2015
Susan Walsh, a forensic geneticist in the School of Science at Indiana University-Purdue University Indianapolis, has been awarded a $1.1 million grant from the U.S. Department of Justice's National Institute of Justice to develop and improve "DNA intelligence" tools that may help identify unknown suspects, perpetrators and missing persons.
Walsh's work, formally known as forensic DNA phenotyping, focuses on the prediction of externally visible characteristics such as eye, hair or skin color from genetic material.
Using DNA from biological samples such as blood, Walsh's new "DNA intelligence" tools will help forensic scientists determine physical appearance information. The tools will be especially useful in cases where conventional DNA profiling is non-informative and an investigation cannot move forward.
"Predicting quantitative color -- not just blue or brown but the precise shade or pigment -- in terms of eye, hair or skin color of an unknown individual provides law enforcement, archaeologists and other investigators with information that can help identify a specific person or determine a potential pool of suspects that may or may not be of interest," Walsh said.
"The tools we are developing will be especially useful in cases where conventional DNA profiling does not provide useful information and an investigation stalls because it's the individual's first crime or the first crime where DNA has been found, hence a profile is not in the DNA database. These new tools will help investigators that lack genetic clues."
DNA profiling -- typically used by law enforcement to identify a suspect and by archaeological researchers such as those who identified the remains of Russian Tsar Nicholas and his family -- compares DNA discovered at a crime scene or archaeological find with DNA stored in a reference database. But DNA profiling is not helpful when no reference DNA exists to test a sample against. The new genetic phenotyping tools that Walsh is developing will let the discovered DNA act as a "biological witness that can do the talking."
Walsh is an assistant professor of biology in IUPUI's School of Science. Her appointment to the IUPUI faculty in 2014 followed a year as a post-doctoral associate at the Yale Molecular Anthropology Laboratory at Yale University. Originally from Ireland, Walsh earned her Ph.D. in forensic genetics from Erasmus University in The Netherlands under Manfred Kayser, a pioneer in forensic DNA phenotyping work. She also holds a master's degree in DNA profiling from the University of Central Lancashire in England.
As a doctoral student in 2013, she was awarded the prize for best oral presentation at the 25th Congress of the International Society for Forensic Genetics in Melbourne, Australia, for her presentation “Predicting skin color from DNA using a model based approach.” She has also been invited to present her work at the next international conference in 2015 in Krakow, Poland.
Walsh is a co-author of a much-discussed study published in December 2014 in the journal Nature Communications. The study confirmed that bones found in 2012 in Leicester, England, are indeed those of King Richard III, who died on the battlefield in 1485. She is a co-developer of HIrisPlex, a forensic DNA phenotyping test used to analyze 11 genes known to contribute to hair and eye color, that was used to predict the king's hair and eye color from ancient bones.
"Our work funded by the National Institute of Justice will be conducted with contributions from undergraduate and graduate students at IUPUI as well as collaborators in the Netherlands, Ireland and Greece," Walsh said. She is a faculty member of the School of Science's highly respected Forensic and Investigative Sciences Program.