The practice began to help people heal quicker, especially in relation to muscle deterioration. A BBC radio documentary in December detailed how gene therapists treat sick children at London's Great Ormond Street hospital - they add a synthetic gene to the patient's genome. The new gene is expressed by the patient's cells and acts like a medicine, permanently incorporated in the bone marrow.
The fear is that if an athlete gene dopes to improve performance, it could result in:
1. A heart attack due to blood thickening
2. Cancer, if cancer-related genes are turned on or off accidentally
3. An immune reaction where the body attacks the virus delivering the gene
4. Permanent effects to the body because, while genes can be added, there's no way yet to remove them.
WADA banned gene doping in 2003. Howman believes it's an area of the doping market where they have parity with cheats: "We formed a sub-committee of outstanding gene therapists back then to work on where the process was going medically. Our scientists, who are from the health companies putting this sort of medicine together, believe they're onto something in terms of detection.
"We're alert to gene therapy as a method of improving good health and sustaining a longer life but I also think back to a survey where athletes were asked would they be prepared to take a substance which would kill them young but guarantee a gold medal. Many said 'yes'. That's the sort of athlete belief in 'invincibility' we're dealing with; they're prepared to ignore potential side effects."
That survey was by Chicago doctor Bob Goldman, a founder of the US National Academy of Sports Medicine, who asked 198 athletes in the 1980s if they would take a performance enhancer for gold medal glory even if it killed them in five years; 52 per cent said 'yes'. Subsequent surveys every two years produced similar responses.
As the Winter Olympics started in Sochi, a new performance-enhancing drug MGF (another muscle-growth enhancer but previously only trialled on animals) was being sold on the black market and billed as being undetectable. It comes as the IOC has promised the most stringent anti-doping programme in the Games history. An estimated 2453 tests are expected, a 14 per cent increase on Vancouver four years ago. A further 1184 targeted tests will be carried out post-competition.
"The scary thing is gene doping's probably already being done in some capacity," Steel says. "There was talk of it ahead of the Beijing Games. However, the odd thing - which may act as a deterrent - is that once we get a proper test it may not be that hard to detect its presence because you can't change back the newly created strands of DNA.
"Gene doping creates the ability to modify a human being to order. It's the next generation of performance-enhancing drugs. We're working on our defence."