Genomes of Archbishop Tutu, Bushman decoded in developing-world health push
Thursday, February 18, 2010
Scientists have deciphered the genetic blueprint of South Africa's Archbishop Desmond Tutu and an indigenous Bushman from Namibia as part of an ambitious and controversial project to bring modern genomic medicine to the developing world.
An international team of researchers decoded every gene of the Nobel Prize-winning anti-apartheid leader and an elderly man named !Gubi, a member of a hunter-gatherer society from the Kalahari Desert. They also cracked the main parts of the genetic codes of three other hunter-gatherers from the Kalahari, whose language consists of a complex arrangement of clicks.
The results, published in Thursday's issue of the journal Nature, are the beginning of a program designed to enable researchers and drug companies to use the most advanced molecular tools of modern "personalized medicine" to help people of all ethnicities and societies. Until now, most of the genomes decoded have involved Europeans.
"The benefits of personalized medicine should be extended to indigenous peoples around the world," said Stephan C. Schuster, a professor of biochemistry and molecular biology at Pennsylvania State University, who helped lead the effort.
The publication of individual human genomes is highly controversial. Only a handful of genomes have been made public, including that of James Watson, who co-discovered the structure of DNA with Francis Crick. Some researchers and advocates for indigenous people said they were worried whether all participants understood the full implications of making their genomes public. The findings could be used against them, denying them claims to property and leading, theoretically at least, to workplace and insurance discrimination or even more sinister ends.
"We're worried how this material will be used," said Pat Mooney, executive director of the ETC Group, a nonprofit advocacy group based in Ottawa. "Will it just be for historic information? Or is it going to turn eventually into profitable products or even dangerous products that could be harmful for these peoples, such as special ethnic bombs?"
An early analysis of the genomes has identified 1.3 million genetic variations that had not previously been found and could lead to important insights, including how to better tailor drugs to people living in southern Africa, the researchers reported. Some AIDS drugs, for example, are less effective in Africans than Europeans, Schuster said.
The analysis has produced tantalizing clues to human evolution. The indigenous people, who are believed to represent the oldest lineage of modern humans, are much more genetically diverse than other populations. They also have genetic variations that might explain their unusually good senses of hearing, vision and smell, physical prowess and enhanced ability to taste bitter, all of which would have evolved to enable them to survive by living off the land.
"They need[ed] to make a living by hunting animals. You have to be very good with long runs and pursuing the wild animals they were preying on. This is all reflected in the genes we find," Schuster said.
Other researchers praised the work.
"I think it's a very exciting paper," said Sarah Tishkoff, an associate professor in the departments of genetics and biology at the University of Pennsylvania. "Africans have not been well represented in genomic and human genetic studies."
Some maintain it is a crucial step for medicine to advance.
"It is nice that a very significant fraction of the genomes that are being done are identified individuals rather than anonymous," said George Church, a professor of genetics at Harvard Medical School who started the Personal Genome Project to encourage people to publish their genomes. "I think it's increasingly important both for medical and nonmedical studies."
Schuster said the project went through numerous reviews by independent authorities in every country involved before going forward. He said he hoped Tutu's prominence as an advocate for indigenous people will encourage others to follow. Knowing Tutu's medical history -- his bouts with polio, tuberculosis and prostate cancer -- will allow researchers to explore those diseases in southern Africans.
"Overall, modern humans from all different regions of the world are all very similar to one another," Schuster said. "At the same time, it is important that we understand those differences that are relevant to medical treatment."