The work was unveiled today at the Annual Meeting of the American Association for the Advancement of Science (AAAS), which publishes Science.
The mapping effort describes 1.58 million single-letter DNA variations across 71 individuals of European American, African American and Han Chinese American ancestry. Although the human genome contains millions more single-letter variations, or single-nucleotide polymorphisms (SNPs), they seem to occur within patterns that have been preserved for thousands of years -- despite the DNA reshuffling that happens from generation to generation. The new mapping effort therefore appears to capture most common human genetic variation, researchers said.
The work is believed to have significant implications for the study of cardiovascular disease, mental illness, and many other conditions thought to result from a complex interplay of multiple genetic and environmental factors.
Researchers made use of the fact that two genes located closer together are far less likely to be reshuffled over generations by the biological process known as recombination. As a result, certain patterns of variation, or "haplotypes," have been preserved across human history. The presence of these patterns, known as "linkage disequilibrium," allowed the Science authors to create a first picture of the structure of human genetic variation based on short- and long-range clustering of single-letter variations (SNPs).
Most common DNA variations are found across all populations and likely date back to the e
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17-Feb-2005