Landmark in DNA risk screening

The results revealed heightened risks of heart disease, cardiac arrest, diabetes and prostate cancer.

Similar assessments could be offered to the general public within the next decade as the cost of genetic mapping plummets, say the researchers.

Professor Stephen Quake, the American scientist who subjected himself to the test after being counselled about the possible consequences, said: "We're at the dawn of a new age of genomics. Information like this will enable doctors to deliver personalised health care like never before."

Several of the study authors warned that major ethical challenges lie ahead and questioned the wisdom of placing no limits on uncovering such sensitive information.

Professor Henry Greely, from Stanford Law School in California, said patients, doctors and geneticists are about to be hit by a "tsunami" of genetic data.

"The experience with Steve Quake's genome shows we need to start thinking – hard and soon – about how we can deal with that information," he added.

Prof Quake, from Stanford University School of Medicine, made headlines last year when he used new technology to sequence his own genome, or genetic code, for less than $50,000 (33,000).

The new study, published today in The Lancet medical journal, used Prof Quake's personal genetic data to make predictions about the fate of his health. Colleagues examined his genetic profile and combined the results with research information from studies about the genetic causes of different diseases. Aspects of his family history were also taken into account, including the sudden death of a distant relative in his sleep at the age of 19.

Prof Quake, who is 40, was screened for 55 conditions, ranging from obesity and type-2 diabetes to schizophrenia and gum disease.

In some cases the normal risk of developing a certain condition for a man of his age was scaled down, and in other cases up.

For instance, he entered the study with a 16 per cent chance of developing prostate cancer in his lifetime.

But after incorporating information about 18 separate genetic variants from 54 studies, Prof Quake's personal risk of prostate cancer was put at 23 per cent.

Conversely, his risk of Alzheimer's disease began at 9 per cent but in light of several protective gene mutations was revised down to 1.4 per cent.

The worst news related to obesity, type-2 diabetes and coronary artery disease. Professor Quake was found to have a more than 50 per cent chance of developing any of these conditions, each of which could affect the development of the other. He also had rare variants in three genes associated with sudden cardiac death.

Prof Quake said of the findings: "It's certainly been interesting. I was curious to see what would show up. But it's important to recognise that not everyone will want to know the intimate details of their genome, and it's entirely possible that this group will be the majority.

"There are many ethical, educational and policy questions that need to be addressed going forward."

Cardiologist Euan Ashley, one of the Stanford scientists, pointed out that the falling cost of genome sequencing would soon put similar screening within reach of the general public.

"The $1,000 (657) genome is coming fast," he said.