In a major breakthrough, scientists have dramatically expanded the volume of genetic information available to medical researchers about complex human diseases and their potential treatments.

An international team of scientists, led by researchers from Children's Cancer Institute Australia for Medical Research (CCIA), the University of New South Wales (UNSW) and Penn State University in the US, sequenced the genomes of indigenous southern Africans and found them to be among the world's most genetically diverse people.

The genomes of four Kalahari Desert Bushmen and an ethnic Bantu are the first to be sequenced from an indigenous population. More than 1.3 million new genetic variants have been added to databases of Human Genome Variation which until now have been largely Eurocentric.

Featured as the cover story in the prestigious journal Nature, the discovery has important implications for medical research, providing potential markers for the origins, treatments and cures for many of the most complex diseases, including cancer. It also raises questions about current scientific assumptions regarding the genetic causes of many diseases.

"The indigenous hunter-gatherer peoples of southern Africa are believed to be the oldest known lineage of modern humans," said study co-leader Dr Vanessa Hayes from the CCIA and UNSW.

"On average, we found as many genetic differences between two Bushmen, than between a European and an Asian.

"This research now provides us with the tools to read the story of human evolution and specifically the story of disease evolution," Dr Hayes said.

Significantly, the genomes are personalised, with all participants named and their medical histories recorded. Among the participants was Nobel Peace Laureate Archbishop Desmond Tutu - a representative of the Bantu community and a Global Elder. The genome sequences will be released to the public and freely accessible online.

"Human variation is vital in determining disease risk and drug response for complex genetic diseases. It is important to include genetic differences from all global populations in research efforts," Dr Hayes said.

"It has been well established that the African continent is the cradle of civilisation and therefore the origin of disease, we just haven't known to what extent.

"We can predict there will be just as much genetic diversity in Australia's Aboriginal community and that would tell another important story of our genetic heritage."

Dr Hayes said the African data is already contributing to the development of a new test based on the human variation found in the study. These 'arrays' will soon be available globally for medical research efforts.

Read more about the background to the study and Dr Hayes' work in a feature story published in the Sydney Morning Herald.

Media contact: Steve Offner, UNSW Media Office, +61(0)2 9385 8107 or +61 (0)424 580 208 | s.offner@unsw.edu.au

Multimedia: A media package including radio grabs, a TV interview with Dr Hayes, and B-roll footage of the research team collecting genetic samples in the field is available - contact the UNSW Media Office.

High-resolution images can be downloaded from Penn State's website and the project photo gallery.