Doctors have for the first time used the genetic profile of an apparently healthy, middle-aged man to predict the risk of him developing dozens of diseases in later life.
Dr Stephen Quake, a 40-year-old scientist at Stanford University in California, was found to be carrying a rare genetic mutation that can cause a sudden and fatal heart attack and other genes that boosted his risk of becoming diabetic and obese to more than 50%.
Quake’s genes revealed how he would respond to different medications, including a number of heartdisease drugs to which he is at risk of reacting badly.
The study, published in the Lancet, is the first to use the full genome of a healthy person to glean information about their future wellbeing and the likelihood of responding well to drug treatments.
Further gene variants suggest Quake has a 23% risk of prostate cancer, but only a 1.4% chance of developing Alzheimer’s disease.
Quake, who sequenced and published his own genome last year, joined forces with colleagues at Stanford to investigate how useful the information was in predicting his future health.
The scientists began by building a database of gene variants and their links to medical conditions, ranging from obesity and schizophrenia to diabetes and gum disease.
Atul Butte, who worked on the study, said: ‘We read thousands of publications and made a list of every single spot in the genome where we know that, for example, the letter A raises the risk of a particular disease, or the letter T confers protection.”
The scientists used a computer to produce a combined risk assessment for 55 medical conditions based on Quake’s genetic make-up, age, gender and other clinical information.
Quake was already aware he carried a gene that put him at risk of a sudden heart attack. The same gene variant was probably responsible for the death of a distant relative, who died unexpectedly in his sleep at 19.
Medical tests showed Quake had no signs of heart defects but, given his risk, doctors suggested he take statins, the cholesterol-lowering drugs usually given to older men at risk of heart disease. ‘We’re at the dawn of a new age in genomics,” Quake said.
‘Information like this will enable doctors to deliver personalised healthcare like never before. Patients at risk for certain diseases will be able to receive closer monitoring and more frequent testing, while those who are at lower risk will be spared unnecessary tests.”
Speaking about the implications of knowing his own genetic makeup, 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.”
The rapid advance of genetic technology will soon make it possible to read a patient’s complete genome for less than R7 500. Doctors expect that the information will become a standard part of a patient’s medical records and will be used to personalise his or her treatment. —