Three years after it was launched with high hopes, the first, massive phase of the International HapMap Project is complete. The goal is to help locate genes behind complex diseases such as diabetes. Francis Collins, director of the National Human Genome Research Institute in Bethesda, Maryland, and a key participant, calls the map "a dream come true." He and others are concerned, however, that, as with any novel tool, researchers may be reluctant to apply it. One reason is that some questions remain about the map's usefulness.
The $138 million HapMap denotes haplotypes, stretches of DNA that are inherited together as unbroken blocks and can be identified by just a handful of DNA markers known as SNPS (single nucleotide polymorphisms). The map allows gene hunters to get away with less (and thus cheaper) DNA sequencing while still, it's hoped, homing in on disease genes. Data from the map, which are freely available online, are already helping narrow the search for genes involved in macular degeneration, dyslexia, and hypertension.
An international consortium led by David Altshuler of the Broad Institute in Cambridge, Massachusetts, and Peter Donnelly of Oxford University in the U.K., announced the draft's completion today at the annual meeting of the American Society of Human Genetics in Salt Lake City, Utah; the map was also published in the 27 October Nature. In a sign of both a desire to exploit the HapMap and confusion about how to do so, more than 500 scientists have signed up for a session at the meeting on how to glean the most from the map.
"The world will be able to use this forever," says David Cox, chief scientific officer of Perlegen Sciences in Mountainview, California, whose company made available in February a HapMap it created. But concern lingers about how the HapMap will perform in the hunt for disease genes. While the Perlegen HapMap differs somewhat from the HapMap created by the international consortium map, says Cox, both should point gene hunters to similar DNA regions--though that hasn't been put to a rigorous test.
International HapMap Project