International Consortium to Create Genetic Variation Map

An international research consortium has been formed to create the next-generation map of the human genome. The project's goal is to speed the discovery of genes related to common illnesses such as cancer, asthma, diabetes, and heart disease.

The US$100 million endeavor is called the International HapMap Project and is expected to require three years to complete. The HapMap will chart genetic variations within the human genome. By comparing individual genetic differences, the researchers believe they can create a tool to help other researchers identify the genetic contributions to many diseases.

To create the HapMap, researchers will take DNA from blood samples collected in Nigeria, Japan, China, and the United States. Initially, researchers will work with samples from 200-400 people in widely distributed geographic regions. A very careful sampling strategy has been developed to ensure that participants can give full informed consent. No medical or personal identifying information will be obtained from the people providing the samples. The samples, however, will be identified by the population from
which they were collected.

Researchers from academic centers, nonprofit biomedical research groups, and private companies in Japan, the United Kingdom, Canada, China, and the United States will analyze the samples to create the HapMap. The results will be made quickly and freely available on the Internet in keeping with the data release approach of the Human Genome Project. The research will be funded by private and public sources, including the US National Human Genome Research Institute (NHGRI, Washington, DC, USA; http://genome.gov).

"The HapMap will provide a powerful tool to help us take the next quantum leap toward understanding the fundamental contribution that genes make to common illnesses like cancer, diabetes and mental illness,” said Francis S. Collins, M.D., Ph.D., director of the NHGRI.

Researchers working on the HapMap will find the chunks into which the genome is organized, each of which may contain dozens of single nucleotide polymorphisms (SNPs). Researchers then only need to detect a few tag SNPs to identify that unique chunk or block of genome and to know all of the SNPs associated with that one piece. This strategy works because genetic variation among individuals is organized in "DNA neighborhoods,” called haplotype blocks. SNP variants that lie close to each other along the DNA molecule form a haplotype block and tend to be inherited together. SNP variants that are far from each other along the DNA molecule tend to be in different haplotype blocks and are less likely to be inherited together.

Once the HapMap is constructed, researchers around the globe will use it to study the genetic risk factors underlying a wide range of diseases and conditions. For any given disease, researchers would use the HapMap tag SNPs to compare the haplotype patterns of a group of people known to have the disease to a group of people without the
disease, a method known as an association study. If the association study finds a certain haplotype more often in the people with the disease, researchers would then zero in on that genomic region in their search for the specific genetic variant. The tag SNPs would serve as signposts indicating that a genetic variant involved in the disease may lie nearby.






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