Experts at Johns Hopkins are joining efforts to
provide names for more than 70 still unidentified bodies
recovered after Hurricane Katrina, which struck last Aug.
29, killing more than 1,200 in Louisiana and Mississippi.
Most of the dead 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,
Johns Hopkins epidemiologists and genetic counselors are
helping Louisiana state officials with the difficult 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," said statistical
geneticist Joan Bailey-Wilson, an adjunct professor at
Johns Hopkins. 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
Johns Hopkins' Elizabeth Pugh, 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.
Bailey-Wilson and Pugh have each visited the Gulf
region in the last few months 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," Bailey-Wilson said.
According to the Johns Hopkins experts, the DNA
identification process following Katrina is a more complex
job than initially thought for several reasons.
Many of the victims lost their identifying personal
effects in the disaster; 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; and many medical and dental records
normally used to match dead bodies with names of the
missing were destroyed, leaving behind few clues as to
whose remains were found. All of these factors make
identification difficult without the aid of DNA testing.
Making matters worse, family members whose DNA is required
to make a match were often 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," said Pugh, an assistant professor at the Johns
Hopkins School of Medicine and head of statistical genetics
at the Center for Inherited Disease Research, an NIH-funded
initiative based at Johns Hopkins. CIDR is a high-tech
facility dedicated to helping scientists at the NIH, Johns
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," she said.
Bailey-Wilson, an adjunct professor at the
Bloomberg School of
Public Health, said 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 was the first Johns
Hopkins counselor to join the effort, having left for the
Gulf region on March 12. Nicole Johnson of the
School of Medicine and the
Kennedy Krieger
Institute's Rebecca Kern were next, departing 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 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 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," said
Bailey-Wilson, noting that family interviews can last from
15 minutes to two hours. The process, she said, is made
more difficult by the fact that many of the relatives may
have moved several times since the hurricane.
Tracking this process for each missing person and
casualty involves tremendous attention to detail, said
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 confidentiality 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.
Genetic testing is made easier, Pugh said, by the
existence of 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.
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