The search for the genetic origins of common diseases has reached a new landmark with the completion of the most detailed map yet of how DNA varies from person to person.
As scientists celebrate the tenth anniversary of the sequencing of the human genome this week, they have been handed a new tool with which to comb it for clues to conditions such as heart disease, diabetes and cancer.
The international 1,000 Genomes Project, which finished its first phase yesterday, has begun to catalogue the common genetic differences between individual people.
It provides an index to the genome that will help researchers to find points of DNA variation that affect health.
Such discoveries promise to lead to the development of new drugs and diagnostic techniques, and to personalised medicine by which patients receive treatments tailored to their own genetic profiles.
Advertisement
Richard Durbin, of the Wellcome Trust Sanger Institute near Cambridge, who co-chairs the project, told The Times: “A decade ago, the Human Genome Project gave us the sequence of an individual human. The 1,000 Genomes Project is giving us the sequence of humanity as a species, of humans as a diverse population of individuals.”
The completion of a first rough draft of the human genome was announced ten years ago on Saturday by Bill Clinton and Tony Blair. While more than 99 per cent of the genome’s three billion pairs of letters are identical in every person, a small fraction vary between individuals.
In the past decade, scientists have found hundreds of common genetic variations that affect the risk of diseases such as cancer and diabetes, or the way individuals respond to certain drugs. These explain, however, only a small fraction of the heritable factors that are known to play a part in these conditions.
The 1,000 Genomes Project will allow scientists to explore this “missing heritability” more deeply, to build a more complete picture of DNA’s influence on health.
The final results from its initial pilot phase were yesterday deposited in a public database, allowing free access to the draft map to any scientist in the world.
Advertisement
The pilot map involved sequencing the genomes of six people in great detail, and combining the results with less comprehensive sequences from another 179 people. A more detailed version is now being prepared, by sequencing the DNA of 2,500 people from 27 ethnic groups.
Dr Durbin said that 500 people’s genomes had been sequenced for this final phase, and another 500 will be finished this year.
He would not discuss details of the insights gleaned so far, because a paper is to be submitted for publication shortly.
An NHS hospital has begun sequencing the DNA of patients for the first time, to investigate how genetic factors contribute to cardiovascular disease.
The £6 million project at the Royal Brompton Hospital in London will examine the 1 per cent of the genome that includes 22,000 genes in 10,000 patients over the next ten years.
Advertisement
Professor Dudley Pennell, who is leading the initiative, said: “The sequencer will bring clear benefits for patients, because we will be able to determine a genetic cause of their cardiac condition to allow accurate diagnosis and personalised treatment. We can now read all the patient’s genes in just one day.”