1000 Genomes Project publishes analysis of completed pilot phase
Produces tool for research into genetic contributors to
human disease
Small genetic differences between individuals help explain why some
people have a higher risk than others for developing illnesses such
as diabetes or cancer. Today in the journal Nature, the 1000
Genomes Project, an international public-private consortium,
published the most comprehensive map of these genetic differences,
called variations, estimated to contain approximately 95 percent of
the genetic variation of any person on Earth.
Researchers produced the map using next-generation DNA sequencing
technologies to systematically characterize human genetic variation
in 180 people in three pilot studies. Moreover, the full
scale-up from the pilots is already under way, with data already
collected from more than 1,000 people.
“The pilot studies of the 1000 Genomes Project laid a critical
foundation for studying human genetic variation,” said Richard
Durbin, Ph.D., of the Wellcome Trust Sanger Institute and co-chair
of the consortium. “These proof-of-principle studies are
enabling consortium scientists to create a comprehensive, publicly
available map of genetic variation that will ultimately collect
sequence from 2,500 people from multiple populations worldwide and
underpin future genetics research.”
Genetic variation between people refers to differences in the order
of the chemical units – called bases – that make up DNA in the
human genome. These differences can be as small as a single base
being replaced by a different one – which is called a single
nucleotide polymorphism (abbreviated SNP) – or is as large as whole
sections of a chromosome being duplicated or relocated to another
place in the genome. Some of these variations are common in the
population and some are rare. By comparing many individuals
to one another and by comparing one population to other
populations, researchers can create a map of all types of genetic
variation.
The 1000 Genomes Project’s aim is to provide a comprehensive public
resource that supports researchers aiming to study all types of
genetic variation that might cause human disease. The project’s
approach goes beyond previous efforts in capturing and integrating
data on all types of variation, and by studying samples from
numerous human populations with informed consent allowing free data
release without restriction on use. Already, these data
have been used in studies of the genetic basis for disease.
“By making data from the project freely available to the research
community, it is already impacting research for both rare and
common diseases,” said David Altshuler, M.D., Ph.D., Deputy
Director of the Broad Institute of Harvard and MIT, and a co-chair
of the project. “Biotech companies have developed genotyping
products to test common variants from the project for a role in
disease. Every published study using next-generation sequencing to
find rare disease mutations, and those in cancer, used project data
to filter out variants that might obscure their results.”
The project has studied populations with European, West African and
East Asian ancestry. Using the newest technologies for
sequencing DNA, the project’s nine centers sequenced the whole
genome of 179 people and the protein-coding genes of 697
people. Each region was sequenced several times, so that more
than 4.5 terabases (4.5 million million base letters) of DNA
sequence were collected. A consortium involving academic
centers on multiple continents and technology companies that
developed and sell the sequencing equipment carried out the
work.
The improved map produced some surprises. For example, the
researchers discovered that on average, each person carries between
250 and 300 genetic changes that would cause a gene to stop working
normally, and that each person also carried between 50 and 100
genetic variations that had previously been associated with an
inherited disease. No human carries a perfect set of genes.
Fortunately, because each person carries at least two copies of
every gene, individuals likely remain healthy, even while carrying
these defective genes, if the second copy works normally.
“ƬƵ is very proud to have played a leadership role in the
Sampling and ELSI (Ethical, Legal, and Social Issues) Committee,”
said Bartha Maria Knoppers, O.C., Ph.D., of the ƬƵ University
Centre of Genomics and Policy, and co-chair of the committee. “We
played a unique role, putting the sampling design people with the
ethics people – selecting populations and criteria and ensuring
consistency across the ethical framework with people in the field.
Our involvement will continue as we move into full-scale studies.”
2,500 samples from 27 populations will be studied over the next two
years. Data from the pilot studies and the full-scale project are
freely available on the project web site,
.
Organizations that committed major support to the project include:
454 Life Sciences, a Roche company, Branford, Conn.; Life
Technologies Corporation, Carlsbad, Calif.; BGI-Shenzhen, Shenzhen,
China; Illumina Inc., San Diego; the Max Planck Institute for
Molecular Genetics, Berlin, Germany; the Wellcome Trust Sanger
Institute, Hinxton, Cambridge, UK; and the National Human Genome
Research Institute, which supports the work being done by Baylor
College of Medicine, Houston, Texas; the Broad Institute,
Cambridge, Mass.; and Washington University, St. Louis, Missouri.
Researchers at many other institutions are also participating in
the project including groups in Barbados, Canada, China, Colombia,
Finland, the Gambia, India, Malawi, Pakistan, Peru, Puerto Rico,
Spain, the UK, the US, and Vietnam.
This document was prepared from a press release issued by the
National Institutes of Health. Please consult the original version
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