"The tubes were bar- coded and shuffled down a series of robotic instruments that first isolated the DNA and then made copies of our compatibility genes," Professor Davis said. "Small beads, each having a different short piece of DNA attached, were added to a solution containing our genes. Beads with DNA just right to bind to one of our compatibility genes are picked out by a sensor, revealing which versions of these genes we have."
Professor Davis discovered his compatibility genes were quite rare, while his wife's were more common. One group of his genes were frequently found in Europe, particularly Eastern Europe, while the other set were common in India or Australia. His wife found she had a gene which would be helpful if she ever suffered an infection with HIV but which also increased her susceptibility to the auto-immune disease ankylosing spondylitis.
He said: "It's not that any of my individual genes are unusual, but the combination of them is rare because they are usually found in different parts of the world. After being pleased that my genes were quite rare - which according to those smelly T-shirt experiments would mean lots of women would like my scent - I then realised this might not be so useful if I ever needed a transplant. In fact the advice they gave me was: Just don't get ill!"
So does the book reveal the perfect set of genes? Professor Davis concludes: "Overall, nobody has a better or worse set of compatibility genes: there's no hierarchy in the system. The fact that we differ is what's important; the way our species has evolved to survive disease requires us to be differen
|Contact: Alison Barbuti|
University of Manchester