Project to map DNA of 1,000 people

An international consortium of scientists plans to study the genomes of 1,000 people in an effort to speed up the diagnosis and treatment of some common diseases.

Researchers from China, the United States and Britain will contribute to the 1000 Genomes Project, the participants said Tuesday.

They hope the new, more detailed genome map they will develop over the next three years will help researchers by reducing the need for time-consuming and costly DNA sequencing to pinpoint the cause of certain diseases.

"This will change the way we carry out studies of genetic disease," U.S. National Human Genome Research Institute (NHGRI) director Dr. Francis S. Collins said in a release. NHGRI is one of the key partners in the project.

Currently, genetic researchers can search for two types of genetic variants related to disease:

• The first group is the very rare, severe variants that cause diseases like cystic fibrosis, which typically affect fewer than one in 1,000 people. It takes years of studies of affected families to identify the variant.
• The second group is more common, but has weaker effects. For example, genetic variants may increase the risk of diabetes or heart disease by 25 per cent or less. 

"Between these two types of genetic variants — very rare and fairly common — we have a significant gap in our knowledge," which the project will fill, said Dr. David Altshuler, the U.S. researcher who is co-chair of the consortium.

Collins from NHGRI said the research will produce a much more detailed genome map. "Our existing databases do a reasonably good job of cataloging variations found in at least 10 per cent of a population. By harnessing the power of new sequencing technologies and novel computational methods, we hope to give biomedical researchers a genome-wide map of variation down to the one per cent level."

Small differences key

Any two humans generally have more than 99 per cent of the same genetic material, but the one per cent difference can help explain why people differ in their susceptibility to disease, response to drugs or reaction to environmental factors. 

But filling in the details on genome maps takes time, and with the data from 1,000 new people, researchers will be able to develop better ways of diagnosing, treating and preventing common diseases, the release said.

The data will be made public through free databases. The work will be done by the Wellcome Trust Sanger Institute in Britain, the Beijing Genomics Institute (BGI) and the NHGRI.

The 1,000 people will be anonymous volunteer donors who have given informed consent. Initially samples will be used from the International HapMap Project, a catalog of common genetic variants that shows where they occur in human DNA and how they are distributed around the world.

HapMap itself is not being used to establish connections between particular genetic variants and diseases, but its data has helped researchers find regions of genomes associated with risk of diseases such as diabetes, prostate and breast cancer and inflammatory bowel disease.

Recent advances spur project

The project "would have been unthinkable only two years ago," but advances in sequencing technology, bioinformatics and population genomics have made it possible, said Britain's Richard Durbin, co-chair of the consortium.

The project will use data from the Yoruba in Nigeria; Japanese in Tokyo; Chinese in Beijing; Utah residents with ancestors in Europe; Luhya and Maasai in Kenya; Toscani in Italy; Gujarati Indians in Houston; Chinese in metropolitan Denver; people of Mexican ancestry in Los Angeles; and people of African ancestry in the southwestern United States.

It will be done in three phases, starting with one-year pilot projects to find the most efficient way of proceeding, and will be followed by a two-year production phase that will generate huge volumes of data.

"The 1000 Genomes Project will generate 60-fold more sequence data over its three-year course than have been deposited into public DNA databases over the past 25 years," said Gil McVean, a University of Oxford researcher who co-chairs the consortium's analysis group. "In fact, when up and running at full speed, this project will generate more sequence in two days than was added to public databases for all of the past year."

"It will benefit all nations by creating a valuable resource for researchers around the globe," said Jun Wang, associate director of BGI.