Hopkins genetics experts aid efforts to identify hurricane Katrina victimsExperts at Johns Hopkins are joining efforts to identify more than 70 bodies recovered after Hurricane Katrina, which struck last Aug. 29, killing more than 1,200 in Louisiana and Mississippi. Most of those killed have already been identified and buried by their families.
Using experience gained in DNA analysis of human remains after the terrorist attacks on Sept. 11, 2001, Hopkins epidemiologists and genetic counselors are helping Louisiana state officials with the complex task of collecting data on family history, a key step in the complex system of DNA testing that state officials must use to match the dead to some of the families of more than 2,000 people still listed as missing from the disaster.
"Both disasters, the attack on the World Trade Center and Hurricane Katrina, have challenged the nation's abilities to handle mass-fatality identification beyond anything ever experienced before," says Joan Bailey-Wilson, Ph.D., an adjunct professor at Hopkins and statistical geneticist. Bailey-Wilson, also co-chief of the Inherited Disease Research Branch of the National Human Genome Research Institute, a member of the National Institutes of Health, has been coordinating national efforts of other geneticists who have volunteered from across the country to assist with victim identification in the Gulf region. She sits on an expert panel, along with Hopkins' Elizabeth Pugh, Ph.D., M.P.H., a genetic epidemiologist, to advise crime lab staff and the coroners' offices in both states responsible for identifying the dead and missing. It is a repeat role for the two, who also served on a panel for the medical examiner's office in New York City after the World Trade Center attacks five years ago.
Bailey-Wilson and Pugh have both visited the Gulf region since November 2005 to assist the Louisiana State Police Crime Laboratory with its efforts to manage the identification process and collection of buccal swabs (of the mouth cavity) from family members of the missing, almost all of whom are from Louisiana.
"Pulling together the infrastructure - from experts in various disciplines and from medical centers across the country - is a skill that forensics experts learned from 9/11, but most of us hoped it was a once-in-a-lifetime event," says Bailey-Wilson.
According to the Hopkins experts, the DNA identification process following Katrina is a more complex job than initially thought.
That is because many of Katrina's missing victims lost their identifying personal effects in the disaster as well. Items such as toothbrushes and hairbrushes, which could contain hair and saliva samples useful in DNA testing, were often contaminated or destroyed by the flooding. Many medical and dental records normally used to match dead bodies with names of the missing were destroyed, leaving few clues behind as to whose remains were found. All of these make identification difficult - without the aid of DNA testing. Making matters worse, family members whose DNA is required to make a match were also displaced by the hurricane, making contact difficult and adding delays to scheduling interviews and appointments for genetic testing.
"One of the lessons learned from 9/11 was that talking to the families about the missing is skilled detective work that can best be done by qualified genetics clinicians and genetic counselors who know the right questions to ask based on what information is needed to fill in the family pedigree," says Pugh, an assistant professor at The Johns Hopkins University School of Medicine and head of statistical genetics at the Center for Inherited Disease Research (CIDR), an NIH-funded initiative based at Hopkins. CIDR is a high-tech facility dedicated to helping scientists at the NIH, Hopkins and elsewhere get a first fix on the regions of the human genetic code containing genes that contribute to complex diseases.
"In today's world of blended families and multiple marriages, not all siblings are biologically related to one another. And trained interview techniques are needed to separate the correct blood relationships involving DNA from the correct social relationships that do not involve any genetic material."
Bailey-Wilson, an adjunct professor at the Johns Hopkins Bloomberg School of Public Health, notes that since September 2005, she has fielded several hundred inquiries from health professionals wanting to help. Of these, more than 70 geneticists from at least 30 medical institutions and private practices have agreed to serve as volunteers in efforts to collect information on family history.
Genetic counselor Julie Albertus, M.S., was the first Hopkins counselor to join the effort, having left for the Gulf region on March 12. Nicole Johnson, Sc.M., C.G.C., and the Kennedy Krieger Institute's Rebecca Kern, M.G.C., were next and departed on March 19. They, like Albertus, worked for one week at the Louisiana Family Assistance Center, formerly called the Find Family National Call Center, in Baton Rouge, La., where investigative operations are based. Plans are under way to send another counselor in June. While there, counselors interview relatives by phone to help construct complex family trees of those presumed lost, a necessary first step in the identification of the dead using DNA testing.
In DNA-marker testing, a person's unique genetic makeup is matched against other previously known samples or, if none exist, samples taken from family members, looking for unique genetic traits or markers specific to the individual or family. The results from the DNA analysis can be used alone or combined with other information, such as body location and distinguishing features, for the state coroner to make an official identification.
Compiling a genetic picture of the family, however, requires an accurate construction of the family tree, so that the minimum amount of genetic information needed can be obtained from siblings or parents, or from cousins and grandparents.
"If a missing aunt, for example, has no children and only one sibling, taking a family history can be simple. However, if a missing aunt has eight children and five siblings, taking down the correct information and determining which relatives are willing to donate DNA samples can be a sensitive and time-consuming task," says Bailey-Wilson, who recalls that family interviews can last anywhere from 15 minutes to two hours. Indeed, she notes, the process is made even more difficult by the fact that many of the relatives are themselves displaced from their homes and may have had to move several times since the hurricane.
Tracking this process for each missing person and casualty involves tremendous attention to detail, adds Pugh, who helped the Louisiana State Police Crime Laboratory's DNA unit set up one of the computer systems and protocols that will guide the identification process. She points out that the whole identification effort follows strict confidentially rules to protect people's privacy.
A person's DNA contains all the genetic information passed down from their parents, but slightly different - though mostly similar - combinations are passed along to siblings. Recognizable but distinct patterns can be seen in cousins, but with greater difficulty, and often requiring specialized tests. Statistical methods are used to compare and match DNA samples to determine how likely it is that genetic markers for an unidentified deceased person fit into the pattern of genetic markers observed in relatives of someone reported missing.
According to Pugh, genetic testing is made easier by commercially available computer software programs to analyze DNA results. These programs can statistically match any individual with genetic material from the same person or with that of family members using as few as 16 unique genetic markers.
"One of our major tasks is to contact the families of those still reported missing and to obtain the DNA samples that will give us the best chance to identify their loved one," says Bailey-Wilson.
"The work of volunteers and staff at the Louisiana Family Assistance Center and the State Police Crime Lab is helping these families, but it is also bridging the gap between genetic and forensic medicine to help make our country better prepared to deal with a massive disaster of this nature," says Bailey-Wilson, who like Pugh, has ties to the Gulf regions, where both studied and worked for several years.
But Johnson takes a much more simple view of her potential and willingness to offer assistance. When asked to describe her motivation for volunteering, she says, "Just knowing of the grief these families are going through is what motivates me. This is something I can do in my own small way to help out."
Last reviewed: By John M. Grohol, Psy.D. on 30 Apr 2016
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