Genetic HapMap Will Change Medicine As We Know It

The International HapMap Consortium today published a comprehensive catalog of human genetic variation, a landmark achievement that is already accelerating the search for genes involved in common diseases, such as asthma, diabetes, cancer and heart disease.

In a paper in the Oct. 27 issue of the journal Nature, more than 200 researchers from Canada, China, Japan, Nigeria, the United Kingdom and the United States describe the initial results from their public-private effort to chart the patterns of genetic variation that are common in the world's population.

The results provide overwhelming evidence that variation in the human genome is organized into local neighborhoods, called haplotypes, that usually are inherited as intact blocks of information.

At the project's outset in October 2002, the consortium set an ambitious goal of creating a human haplotype map, or HapMap, within three years. The Nature paper marks the attainment of that goal with its detailed description of the Phase I HapMap, consisting of more than 1 million markers of genetic variation, called single nucleotide polymorphisms (SNPs).

The consortium is also nearing completion of the Phase II HapMap that will contain nearly three times more markers than the initial version and will enable researchers to focus their gene searches even more precisely on specific regions of the genome.

Any two unrelated people are 99.9 percent identical at the genetic level. However, it is important to understand the 0.1 percent difference because it can help explain why one person is more susceptible to a disease or responds differently to a drug or an environmental factor than another person.

Many other discoveries lie on the horizon as the HapMap empowers studies of other common diseases, including diabetes, Alzheimer's disease, cancer, schizophrenia, asthma, hypertension and heart disease.