Results of a project that has mapped the genetic material, or genomes, of 1,092 individuals from 14 countries will help researchers interpret genetic changes in people with disease. The first phase of the so-called '1,000 Genomes Project,' published in the journal Nature, profiles the rare and common genetic variations in the human species.

Scientists believe that rare variants in human DNA – found in just one of every 100 people or fewer – are the major contributors to common complex diseases such as cancer, heart ailments and diabetes. The multinational team of researchers divided the sample populations into four ancestry groups – European, African, East Asian and the Americas – and found that these rare gene variants tend to be restricted to specific geographic regions.

Data from the study, which is available on a public database, is already being used to screen cancer genomes for mutations that might suggest new therapy approaches, and to speed diagnoses of diseases. The next phase of the project will include as many as 3,000 individuals.

Population groups whose DNA was sampled in the project include the Yoruba in Ibadan, Nigeria; the Luhya in Webuye, Kenya; the Han Chinese in Beijing and the Southern Han Chinese; people with African ancestry in the southwestern U.S.; the Colombians in Medellin; and the Iberian populations in Spain.