9/11 panel combines forensics, genetics to ID disaster victims

Diagnostics & Imaging Week

A panel of experts convened from the National Institutes of Health (NIH; Bethesda, Maryland) and other institutions after 9/11 to serve as an advisory panel to develop a process to identify victims using DNA collected at the site of the disaster has reported the identification of about 850 of those missing.

In an article in the Nov. 17 issue of the journal Science, the group, called The Kinship and Data Analysis Panel, said that the 850 identified constitute about one quarter of the 2,749 missing in the collapse of the World Trade Center towers.

The article also makes recommendations to improve DNA identification in the event of future terrorist attacks or mass disasters.

“I think that we were pleased that we were able to do this well,” Joan Bailey-Wilson, PhD, a statistical geneticist and senior investigator at the National Human Genome Research Institute (NHGRI; Bethesda), told Diagnostics & Imaging Week. The NHGRI furnished the 9/11 panel with the statistical expertise necessary to reduce the risk of mis-identification.

At the beginning,” she said, “when you realized how damaged so many of the samples were, it was really pretty amazing to think that this many were able to be identified, and it was an unbelievably hard job to do this well.”

Most of the identification were made using standard methods used in forensic testing, but when DNA sample were not in perfect conditions, new techniques for developing better samples or analyzing the samples available were used or developed for the purpose, according to the NIH.

“The process was what was so amazing,” Bailey-Wilson said. “Every time the medical examiner’s office hit a brick wall, they’d come back and say, ‘What else can we do?’ And a lot of new [technology] was put to use and new combinations of things, [whereby] cutting edge genetics were moved into forensics by this group of people.”

More than 20,000 tissue fragments were collected at the site of the World Trade Center collapse, all of which had to be catalogued and analyzed, the NIH said.

A key problem was related to the location of the disaster, with researchers finding that the DNA samples derived from the tissue fragments often were mixed with inorganic building material. Often these materials were fused together, since temperatures at the disaster site sometimes exceeded 1,800 degrees F, according to the NIH.

Bailey-Wilson explained that part of what has to be done for DNA identification is to acquire a separate sample of DNA from the person thought to be missing in order to find an exact match with the samples taken at the site. Those separate samples might come from a hairbrush or from the saliva from the missing person’s toothbrush.

“If you type 13 different loci . . . which is the standard of loci that most forensics experts around the country use,” and if those 13 loci match on both the tissue from the missing person and the reference sample, then “it’s pretty certain that really is the person,” she said.

While there were stored samples readily available for firefighters – usually a blood sample – due to the nature of their jobs, such samples are not stored or available for the average person.

Thus, in many cases, there were no reference samples; in other cases, she said, the experts might have had eight or 10 items from the missing person, but not all of these samples were usable for testing, Bailey-Wilson told D&IW.

When that was the case, the experts turned to genetics, or in other words, the family tree, such as DNA taken from cheek swabs of next of kin.

“That’s where my role came in,” Bailey-Wilson said, “in helping to talk about what were good ways to make those matches.”

KADAP, in conjunction with New York City’s chief medical examiner, has determined that no further identification can be made at this time using the DNA samples collected.

KADAP included not only Bailey-Wilson, but also Lesle Biesecker, MD, a medical geneticist at the NHGRI and the first author of the paper published in Science. Biesecker provided expert advice about kinship analysis, communicating relevant information about genetic testing to the families, and human subject issues, according to the NIH.

KADAP was organized and funded by the National Institute of Justice, an agency of the U.S. Department of Justice, based on a request from New York City’s chief medical examiner. The New York State Police Forensics Identification Center was responsible for any reference DNA samples and several private laboratories tested samples from the World Trade Center site. The final identifications were made by the Office of Chief Medical Examiner of New York City.

The NIH said most of the identifications were able to be done using standard testing methods employed by forensic scientists.

The panel also made suggestions on how to improve DNA-based identification efforts in the event of any future mass disasters or terrorist attacks.

KADAP members recommend that, based on their ex-perience with the World Trade Center effort, similar panels should identify the criteria for determining when an identification effort should be concluded, when it is deemed that no further progress can be made.

Other recommendations include:

• Conducting more research to develop more sensitive forensic DNA typing systems.
• Improving software to integrate analytical, database and workflow functions.
• Designing processes to test and validate novel identification procedures as they are being developed.

In a statement, NIH Director Elias Zerhouni, MD, said, “This effort presented the group with some overwhelming challenges in the face of such an unprecedented tragedy, but they came together at this time of national crisis and developed a process that provided better results than many would have expected. We owe them a debt of gratitude for providing the scientific expertise and compassion needed to help families and friends identify their loved ones.”

The National Institute of Justice said it plans to publish a separate report outlining lessons learned from the work of the KADAP panel to serve as a model for other mass casualty DNA investigations. Authorities have already used the report to help identify victims of last year’s South Asian tsunami and of Hurricane Katrina.