Humans carry up to 100 genes that are responsible for diseases such as diabetes and cancer, a new study has found.
And there are about 300 genes which are so flawed that they don’t work at all, according to a team of international scientists who analysed the tiny genetic differences between individuals under the “1,000 Genomes Project”.
According to the scientists, who compiled the first ever “catalogue” of genetic faults, although the human genome is estimated to contain up to 25,000 genes in total, only 75 to 100 genes are known to have links to inherited diseases.
In many cases, they will not cause any problems, with people carrying the disease but not becoming ill themselves.
But learning more about how they, and other flaws, trigger disease could lead to new drugs, genetic tests and even ways of preventing ill health, said the scientists.
Dr David Altshuler of Massachusetts General Hospital in Boston said: “It is clear that disease is influenced by inheritance but also by environment, behaviour and by chance.”
“Moreover it is clear that most diseases are influenced by many genes and by many variations in many genes. It is not a simple problem,” Dr Altshuler was quoted as saying by the Daily Mail.
The research, which involved reading the DNA of more than 800 volunteers from around the world, is expected to offer the deepest insight yet into the human genome, or genetic blueprint, and could shed new light on what makes us human.
It will also help scientists work out why some people are more susceptible to disease than others, the researchers said.
Dr Altshuler said: “The reason we do this (research) is because we live in time when one of the great scientific opportunities is to use this new ability to read DNA in our population.
“We do believe in the long-run this is a very valuable and promising approach to learn new things about the basis of disease and if we do that as a field and then biological follow-up occurs this has promise to contribute to improvements in human health.”
Results from the pilot phase of the ambitious project are published in the journals Nature and Science.
Under the project, scientists have also started reading parts of the human blueprint that were inaccessible until now.
Some of these “untouchable genes” could help explain why the human brain is so much more complex than the ape version.
Dr Evan Eichler of the University of Washington said: “We see a significant number of genes that would be particularly sexy candidates for ‘human-mentation’.”
Advances in technology and a reduction in costs means the project will sequence the DNA of 2,500 participants before it finishes in two years’ time.
