04 May 2010
ByAppeared in BioNews 556
Whole genome analysis has been used for the first time to gather clinically-useful information about the risk of developing diseases later in life. Stephen Quake, an apparently healthy, middle-aged professor of bioengineering at Stanford University in California, volunteered to have his entire genetic code screened. He was found to be at increased risk of developing diabetes, some cancers and of having a heart attack. The study was carried out by Dr Euan Ashley and colleagues at Stanford University and was published in The Lancet.
Professor Quake, who sequenced and published his own genome last year, first received genetic counselling to prepare him for the possibility that the analysis could reveal a serious disease. His genome sequence was then scanned for DNA variations, which are known to be associated with 55 medical conditions. The researchers combined his 'genetic map', age and other clinical information to produce a combined risk assessment.
The results showed Quake has a higher than expected risk of developing type two diabetes, obesity and some tumours, but a reduced risk of Alzheimer's disease. Focusing on his family history of heart problems, the researchers found an increased likelihood of coronary heart disease and identified rare genetic variations associated with sudden heart failure. The analysis also revealed information about his predicted response to the blood thinning drug warfarin, which has potential implications for future treatment. Dr Ashley explained how this approach would allow medical decisions to be made 'by taking into account both genetic risk and predisposition to response to medications we're going to use'.
Commenting on the experience, Professor Quake said: '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.' He added that the study marks 'the dawn of a new age in genomics', when doctors will be able to provide personalised medical advice based on precise tests of patients' genetic make-up.
Dr Philippa Brice, from the Foundation for Population Health Genomics, said in the Guardian that: 'prompt action is needed to consider how health services should be preparing for the onset of whole genome-sequencing as a clinical tool, including such areas as the development of the necessary bioinformatic and IT systems, wider societal and regulatory issues related to the more extensive use and storage of personal genomic information, and the development of a health professional workforce with the necessary knowledge and skill'.
Furthermore, she said, it was important to distinguish: 'between genuinely useful and irrelevant, misleading or even harmful genetic information'. In an accompanying article, Professor Nilesh Samani from the University of Leicester warned that ethical questions, such as who should have their genome sequenced and who should have access to the data, also needs to be addressed before such genetic testing can become a feasible clinical tool.