That old saw about bolting the stable door after the horse has fled
is worth bearing in mind when thinking about new techniques for manipulating
the human germ line. The use of genetic engineering techniques to change
permanently the make-up of humans has always seemed so shocking that everyone
has assumed that there will be a long public debate before the techniques
are ever used. But with the appearance of a patent application for a germ-line
manipulation technique which mentions human applications (see This Week),
this assumption needs to be questioned.
The patent application describes a method for removing spermatogonia
– the cells that develop into sperm – from a man, altering genes in them,
and returning the cells to the testes. The outcome is a man who permanently
produces sperm carrying genes different from his own.
The technique has not been developed with humans in mind. Ironically,
horse breeders might be among those keen to use it. It could enable them,
for example, to replace an ordinary stallion’s spermato-gonia with cells
taken from a prize-winning racehorse. But it is significant that the patent
also describes the possible use of the technique in men – the first time
that anyone has applied for a patent on a germ-line manipulation technique
which specifically lists such a use.
Other tried and tested techniques for germ-line therapy already exist.
Biotech-nologists have mastered ways of injecting a gene carrying a new
trait either into an ovum, or into a primitive embryo and have produced
genetically engineered animals which can pass on their new traits to their
offspring. There’s Tracy the sheep in Scotland, for example, and several
new breeding lines of chickens, pigs, goats and rodents have also been created.
Technology often outstrips society’s ability to deal with it. The difference
with germ-line gene therapy is that even now, no one seems willing to confront
the public with the awesome potential to permanently change human genetic
make-up and to talk about what is, and what isn’t acceptable.
If they don’t – and soon – someone, somewhere will put already exisiting
technologies to work. Then it really will be too late to bolt the door.