NHGRI'S LARGE-SCALE SEQUENCING RESEARCH NETWORK SETS ITS SIGHTS O N DISEASE TARGETS

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U.S. Department of Health and Human Services 
NATIONAL INSTITUTES OF HEALTH 
NIH News 
National Human Genome Research Institute (NHGRI)  
http://www.genome.gov/

FOR IMMEDIATE RELEASE: Monday, October 17, 2005 

CONTACT: Geoff Spencer, 301-402-0911, spencerg@xxxxxxxxxxxx 
 
NHGRI'S LARGE-SCALE SEQUENCING RESEARCH NETWORK SETS ITS SIGHTS ON DISEASE
TARGETS 
NHGRI Effort Expands to Include Medical Sequencing 

Bethesda, Maryland -- In what promises to be a significant step forward in
the genome era, the National Human Genome Research Institute (NHGRI), one of
the National Institutes of Health (NIH), today announced plans to devote a
portion of its large-scale sequencing capacity to efforts aimed at
identifying the genetic roots of specific diseases that have long eluded
gene hunters. 

The National Advisory Council for Human Genome Research (NACHGR) recently
approved a plan for NHGRI's Large-Scale Sequencing Network that, for the
first time, includes a portfolio of "medical sequencing" projects. Projects
given the highest priority will use large-scale sequencing over the next few
years to identify the genes responsible for dozens of relatively rare,
single-gene (autosomal Mendelian) diseases; sequence all of the genes on the
X chromosome from affected individuals to identify those involved in
sex-linked diseases; and to survey the range of variants in genes known to
contribute to some common diseases. The launch of each project will depend
on a number of factors, including the strategic selection of specific
diseases and the availability of patient samples with appropriate informed
consent. 

In addition to the new focus on medical sequencing, the plan continues
NHGRI's emphasis on using comparative genomic sequencing analysis to
understand the structure and function of the human genome and the biological
processes at work in human health and disease. The strategy includes a mix
of whole genome sequencing, genome mapping and sequencing of genomic regions
chosen for their scientific merits. Additionally, NACHGR approved the
refinement of several existing draft genome sequences and targeted a group
of seven additional non-mammalian organisms for sequencing. 

"Medical sequencing has the potential to make a substantial impact on both
biological and medical research. While many of the genes we will initially
be pursuing are responsible for rare disorders, what we learn from rare
disorders often has profound consequences for our understanding of more
common conditions. Thus we expect the cumulative impact of this acceleration
in disease gene discovery to be profound, as many of the discoveries will
shed new light on the biological pathways involved in human health and
disease," said NHGRI Director Francis S. Collins, M.D., Ph.D. 

The first medical sequencing project, predicted to begin in the next year,
will be a demonstration project to find the genetic variations responsible
for seven rare, autosomal Mendelian disorders. The demonstration project
will establish the best procedures for obtaining quality samples, for
determining the minimum number of affected and control samples needed, and
for deciding how the data will be released to the biomedical research
community. 

Among the demonstration projects under consideration are those to identify
the genes responsible for the familial forms of atrial fibrillation, a major
risk factor for heart failure and stroke; thoracic aortic aneurysms, which
are life-threatening tears in the major artery of the heart; and dominant
restrictive cardiomyopathy, another heart disorder. By understanding the
familial forms of these diseases, scientists can apply what they learn to
uncover the genetic components underlying the more common types of these
heart disorders in the human population. 

The other demonstration projects will target the genes for four other rare
disorders: paroxysmal kinesigenic choreoathetosis, a neurological condition;
neovascular inflammatory vitreoretinopathy, a blinding disorder;
lymphedema-cholestasis syndrome, a hereditary disorder causing jaundice and
leg swelling; and Joubert syndrome, a rare brain and physical development
disorder. 

NHGRI estimates that there are at least 50 to 100 additional projects in the
scientific community that could benefit from the brute force and specialized
tools of large-scale sequencing. In order to make an accurate assessment and
gather community input into this program, NHGRI has issued a Request for
Information to seek additional examples of such diseases from investigators
around the world. The deadline for responses is Nov. 4. NHGRI will also hold
an open discussion on Oct. 28 during the upcoming meeting of the American
Society for Human Genetics in Salt Lake City to seek additional input from
the human genetics community. NHGRI will analyze the input from these
sources and determine the ultimate size of this aspect of medical sequencing
as well as the best way to select those projects that offer the most
promise. 

Another medical sequencing project will be an effort to identify the genetic
changes that result in diseases known as X-linked disorders. The human
genome consists of 22 matching pairs of chromosome, referred to as autosomal
chromosomes, plus a non-matching pair referred to as the sex chromosomes.
The sex chromosomes, which are called X and Y, determine whether a person is
female (XX) or male (XY). Any defects in genes on the X chromosome are often
more apparent in males than females because the Y chromosome does not carry
corresponding genes to compensate. 

While researchers have identified the genes responsible for a number of
X-linked disorders, the precise genetic basis for approximately 130 of these
disorders remains to be determined. The study would entail completely
sequencing all genes on the X chromosomes of individuals affected with the
disorders, and looking for variations that consistently correlate with each
disorder. 

The other medical sequencing project given priority will attempt to
characterize the entire spectrum of variation, both rare and common, in a
significant number of candidate genes for common diseases. Genes known to
influence high blood pressure, cholesterol and body weight will be targeted.
Samples would be sequenced from hundreds to thousands of individuals from
existing large cohort studies examining specific diseases, such as
atherosclerosis or diabetes. 

As part of the effort to select medical sequencing projects, NHGRI has
included a working group to examine the ethical, legal and social issues
relevant to the new medical sequencing projects. Many of these issues, which
include obtaining informed consent from volunteers who plan to donate
samples or who have already donated samples for other research projects,
protecting the privacy of such volunteers, and understanding when, or how to
report clinically relevant results back to volunteers, are similar to those
encountered in much of human genetics research. The group will also address
data release and intellectual property procedures. 

In addition to the new focus on medical sequencing, NHGRI is continuing its
ongoing effort to sequence other organisms' genomes, with the aim of
deepening our understanding of human biology and evolution. Since the human
genome and that of other mammalian and non-mammalian genomes have all
evolved from a common ancestor, scientists can use the genome sequences of
the non-mammalian animals to learn more about how, when and why the genomes
of humans and other mammals came to be composed of certain DNA sequences.
Such studies also provide new insights into the function of those sequences,
the organization of genomes, and expand our understanding of the biological
basis of certain infectious diseases. 

NHGRI has selected seven non-mammalian organisms or groups of organisms for
the next round of sequencing. Three of the organisms have been targeted for
"high-quality draft" sequencing. They are: the green anole lizard ("Anolis
carolinensis"), zebra finch ("Taeniopygia guttata") and body louse
("Pediculus humanus"). Researchers will also construct physical genetic maps
and do some targeted genomic sequencing of two sandflies ("Lutzomyia
longipalpis" and "Phlebotomus papatasi"), and will obtain a low coverage
sequence of the Africanized honey bee ("Apis mellifera scutellata") for
comparison with the honey bee genome sequence. Finally, the genomes of 100
bacteria cultured from the normal human gut will be sequenced. 

"We are continuing to focus on those organisms that will reveal the greatest
amount of information about the major biological innovations that have
occurred throughout evolution, with emphasis on learning more about our own
genome. Genomic information from a wide array of species is proving useful
in many areas of biomedical research," said Mark S. Guyer, Ph.D., director
of NHGRI's Division of Extramural Research. 

The green anole lizard will be the first reptile to have its genome
sequenced. Sequencing this reptile will provide a valuable comparison to the
chicken, human and other mammalian genomes. The green anole lizard is also a
well-established experimental model for neurobiology, endocrinology and
reproduction. 

Selected for physical mapping earlier this year, the zebra finch will now be
sequenced to a high-quality draft. The zebra finch was chosen because it is
a major model system for understanding brain development, learning and
memory. Because it is related to the chicken, whose genome has already been
sequenced, it will be possible to leverage the chicken genome to get more
insight from the zebra finch genome sequence. 

The body louse, which possesses the smallest measured insect genome, is a
vector for "Rickettsia prowazekii", a category B bioterrorism agent that
causes typhus. The two sand flies targeted for sequencing are major vectors
of leishmaniasis, a parasitic disease responsible for disfiguring skin
lesions and damage to the spleen, liver and bone marrow. It is estimated
that 12 million people are infected worldwide and that this disease causes
more than 60,000 deaths each year. In fact, approximately 1,200 soldiers
deployed during the Gulf War have contracted the skin lesions caused by
leishmaniasis. Sequencing the genomes of the sandflies will give researchers
a better understanding of this disease and possibly aid the development of
vaccines. 

The human gut microbiome project represents an exciting new research area
for NHGRI, which, except for the bacterium "E. coli", has focused its
large-scale sequencing program on higher organisms rather than bacteria. But
there are more bacterial cells in the human gut than there are human cells
in the entire human body. Furthermore, human gut microbes have a profound
effect on many human physiological processes, such as digestion and drug
metabolism, and play a vital role in disease susceptibility. Sequencing the
genomes of these 100 microorganisms found in the human gut, which represent
a significant, but unknown fraction of all microbes in the human gut, is
expected to provide a much more complete picture of this aspect of human
biology than has ever been available previously. It is hoped this new
information could lead to improved diagnostic tools for monitoring human
health. 

The latest NHGRI sequencing plan will also support the refinement of the
rat, chicken and dog genomes. All are important model organisms, and their
genomes are used to identify features that are similar, or conserved, among
the genomes of the human and other mammals. Sequences that have been
conserved throughout evolution often reveal important functional regions of
the human genome. To learn more about the field of comparative genomic
analysis, go to: www.genome.gov/10005835. 

Sequencing efforts will be carried out by the NHGRI-supported Large-Scale
Sequencing Research Network, which consists of five centers: Agencourt
Bioscience Corp., Beverly, Mass.; Baylor College of Medicine, Houston; the
Broad Institute of MIT and Harvard, Cambridge, Mass.; the J. Craig Venter
Science Institute, Rockville, Maryland; and Washington University School of
Medicine, St. Louis. Assignment of each organism to a specific center or
centers will be determined at a later date. 

NHGRI's process for selecting sequencing targets begins with three working
groups comprised of experts from across the research community. Each of the
working groups is responsible for developing a proposal for a set of genomes
to sequence that would advance knowledge in one of three important
scientific areas: to identify areas in genetic research where the
application of high-throughput sequencing resources would rapidly lead to
significant medical advances, understanding the human genome and
understanding the evolutionary biology of genomes. A coordinating committee
then reviews the working groups' proposals, helping to fine-tune the
suggestions and integrate them into an overarching set of scientific
priorities. The recommendations of the coordinating committee are reviewed
and approved by NHGRI's advisory council, which in turn forwards its
recommendations to NHGRI leadership. For more on the selection process, go
to: www.genome.gov/Sequencing/OrganismSelection. 

The genomes of a number of organisms have been or are being sequenced by the
large-scale sequencing capacity developed by the Human Genome Project. A
complete list of organisms and their sequencing status can be viewed at
www.genome.gov/10002154. 

High-resolution photos of many of the organisms being sequenced in the
Large-Scale Sequencing Program are available at: www.genome.gov/10005141. 

NHGRI is one of the 27 institutes and centers at NIH, an agency of the
Department of Health and Human Services. The NHGRI Division of Extramural
Research supports grants for research and for training and career
development at sites nationwide. Additional information about NHGRI can be
found at its Web site, www.genome.gov.

The National Institutes of Health (NIH) -- "The Nation's Medical Research
Agency" -- includes 27 Institutes and Centers and is a component of the U.
S. Department of Health and Human Services. It is the primary Federal agency
for conducting and supporting basic, clinical, and translational medical
research, and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and its programs,
visit http://www.nih.gov.
  
##
 
This NIH News Release is available online at:
http://www.nih.gov/news/pr/oct2005/nhgri-17.htm.

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