Research: 1000 Genomes Project23 January 2008 |
An international research consortium has announced the 1000 Genomes Project, an ambitious effort to sequence the genomes of at least 1000 people to create the most detailed and medically useful catalogue to date of human genetic variation.
Any two humans are more than 99 per cent the same at the genetic level: the small fraction of genetic material that varies among people can help to explain individual differences in susceptibility to disease, response to drugs or reaction to environmental factors.
The 1000 Genomes Project therefore aims to produce an extremely detailed catalogue of human DNA variation that can be used in future studies of people with particular diseases.
Across most of the human genome, the researchers will be looking for variations that are present at a frequency of 1 per cent or more in the population; in genes, however, the goal is to find variations that are present in 0.5 per cent or less of the population. Producing a map at this resolution, which is unmatched by current resources, is likely to require sequencing of genomes of at least 1000 people.
Using recently developed catalogues of human genetic variation, such as the HapMap and Wellcome Trust Case Control Consortium, researchers already have discovered more than 100 regions of the genome that contain genetic variants associated with susceptibility to common human diseases such as diabetes, coronary artery disease, prostate and breast cancer, rheumatoid arthritis, inflammatory bowel disease and age-related macular degeneration.
However, researchers often must follow those studies with costly and time-consuming DNA sequencing to help pinpoint the precise genetic variants that are associated with a disease. The new map will enable researchers to zero in quickly on such variants, speeding efforts to use genetic information to develop new strategies for diagnosing, treating and preventing common diseases.
Several different types of genetic variation will be mapped in the project: single-letter differences in DNA (single nucleotide polymorphisms or SNPs), and structural variants such as rearrangements, deletions or duplications of segments of the human genome. The importance of these latter variants has become increasingly clear in the past 18 months from the Wellcome Trust Sanger Institute's Copy Number Variation Project and similar research, which show that structural variants may play a role in susceptibility to certain conditions, such as mental retardation and autism.
The sequencing work will be carried out at the Wellcome Trust Sanger Institute, the Beijing Genomics Institute in China, and the National Human Genome Research Institute (NHGRI) Large-Scale Sequencing Network, which includes the Broad Institute of MIT and Harvard; the Washington University Genome Sequencing Center at the Washington University School of Medicine in St. Louis; and the Human Genome Sequencing Center at the Baylor College of Medicine in Houston.
Among the populations whose DNA will be sequenced in the 1000 Genomes Project are: Yoruba in Ibadan, Nigeria; Japanese in Tokyo; Han Chinese in Beijing; Utah residents with ancestry from northern and western Europe; Luhya in Webuye, Kenya; Maasai in Kinyawa, 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 south-western United States. These people will be anonymous and will not have any medical information collected on them.