1,000-genomes study is 'guidebook' to how genes vary

A landmark project that has sequenced 1,092 human genomes from individuals around the world will help researchers to interpret the genetic changes in people with disease.(See: Scientific team sequences 1092 human genomes to determine standard range of human genetic variation).

The first study to break the '1,000-genomes barrier' will enable scientists to begin to examine genetic variations at the scale of the populations of individual countries, as well as guiding them in their search for the rare genetic variations related to many diseases.

The vast majority of genetic variation is shared with populations around the world but it is thought that a lot of the contribution to disease may come from rare variants of genes, found in 1 in 100 people or fewer. Researchers need to find these rare variants to see who has them and work out how they might contribute to a range of conditions from multiple sclerosis to heart disease and cancer.

The international team behind the 1,000 Genomes Project found that rare gene variants tend to be restricted to particular geographic regions, because they typically arise from more recent mutations since humans spread across the world. By, for the first time, drilling down to genetic variants occurring at the scale of 1 in 100 people this study will enable researchers to interpret an individual's genome in the context of the genetic variation found in their own national population: identifying differences between genomes from 14 countries from Europe (including the UK) the Americas, East Asia and Africa.

A report of the research is published this week in the journal Nature.

"We are all walking natural experiments; some of our genes are switched off, some are active, whilst others are overactive," says professor Gil McVean of Oxford University, the lead author for the study. "Our research has found that each apparently healthy person carries hundreds of rare variants of genes that have a significant impact on how genes work, and a handful (from two to five) of rare changes that have been identified as contributing to disease in other people."