Scientists have completed a catalogue of human genetic diversity, that they have made available for free over the Internet.
The catalogue, they hope, will help tailor medical treatments to an individual's genetic makeup.
The team, known as the HapMap consortium, includes scientists from Canada, China, Japan, Nigeria, the United Kingdom and the United States. It published its results today (27 October) in Nature.
Most human genes have hundreds of different forms. Although there are about ten million of these 'gene variants', they are generally inherited in groups. One person generally inherits several of these clusters.
The newly completed catalogue contains more than one million of a particular type of gene variant, known as a 'single nucleotide polymorphism', or SNP.
The team identified which SNPs are inherited together. This means that researchers looking for a particular cluster of SNPs in a patient, for example to determine if it causes a genetic disease, only need to look for one of them and can assume the rest of the cluster will have been inherited as well.
In an accompanying article in Nature, David Goldstein and Gianpiero Cavalleri of Duke University in the United States, say this initial version of the map of human genetic diversity is an "unprecedented gift" for geneticists.
Because a person's gene variant could determine how well they respond to a drug, the catalogue will most likely be used to tailor medicines to a patient's genetic makeup.
But the catalogue is not without flaws, say Goldstein and Cavalleri, primarily because it does not include rare genetic variants.
The HapMap consortium created their catalogue with DNA from four test populations, including a Nigerian group and a Chinese one. Whether this data is applicable to the rest of the world remains to be seen, say Goldstein and Cavalleri.
Reference: Nature 437, 1299 (2005)