Human genetic variation project underway

An international consortium that aims to catalogue patterns of human genetic variation has published a detailed description of its approach, partly to ensure that all the scientists involved receive credit for their work. The 'HapMap' project, launched in October 2002, is looking at DNA samples from 270 people from around the world, to help uncover the genetic differences linked to illnesses such as heart disease, cancer and diabetes.

The HapMap scientists are looking at genetic markers (called single nucleotide polymorphisms, or SNPs) that have been inherited together in a block over many generations, indicating that they are physically close to each other. To identify these 'haplotype blocks', researchers will study people originating from China, Nigeria, Japan and Europe. Between them, these populations are thought to represent the majority of human genetic variation.

Once catalogued, the haplotype blocks will provide a 'shortcut' for researchers trying to identify genes involved in common diseases. Instead of having to sequence a person's entire genome, future studies could look at SNP variations in key positions, and infer the surrounding DNA sequence, the scientists say. 'The HapMap will provide a critical resource that has previously been missing and will allow connecting variation in the genome with risks of human disease' said Francis Collins, director of the US National Human Genome Research Institute.

An international collaboration published a consensus human genome sequence in April 2003, data which they made freely available to the scientific community. The HapMap project also wishes to create a public resource, but wants to avoid the publication wrangles that surrounded the Human Genome Project. For this reason, as well as to inform other researchers of its plans, the HapMap consortium has published its initial results and methods in the journal Nature. This will allow those taking part to cite published papers, whilst continuing to release data immediately.