Scientists have decoded the genomes of more than 1,000 people from 14 ethnic global groups, to trace rare and common diseases to their very roots.
The 1,000 Genomes Project involved some 200 scientists at Washington University School of Medicine in St. Louis and other institutions. Eventually, the initiative will involve 2,500 individuals from 26 populations.
The raw information thrown up by the gigantic project took up some 180 terabytes of hard-drive space, enough to fill more than 40,000 DVDs. All of the information is freely available on internet, the journal Nature reported.
"We estimate that each person carries up to several hundred rare DNA variants that could potentially contribute to disease. Now, scientists can investigate how detrimental particular rare variants are in different ethnic groups," said Mardis, according to a Washington statement.
At the genetic level, any two people are more than 99 percent alike. But rare variants - those that occur with a frequency of one percent or less in a population - are thought to contribute to rare diseases as well as common conditions like cancer, heart disease and diabetes.
Rare variants may also explain why some medications are not effective in certain people or cause side-effects such as nausea, vomiting, insomnia and sometimes even heart problems or death.
Researchers found that most rare variants differed from one population to another, and that they developed recently in human evolutionary history, after populations in Europe, Africa, Asia and the Americas diverged from a single group.
"This information is crucial and will improve our interpretation of individual genomes," said another co-principal investigator Richard K. Wilson, director of The Genome Institute and a pioneer in cancer genome sequencing.
All study participants submitted anonymous DNA samples and agreed to have their genetic data included in an online database.