Call for debate over engineering humans

Inserting genes into animal cells is a scientific reality

A leading British fertility expert is calling for a public debate over whether scientists should be allowed to genetically engineer humans.

Lord Winston believes the approach of modifying human genes that would be passed on in the sperm or egg could one day be used to eradicate serious genetic diseases.

But he says there will be inherent dangers in altering the DNA of future generations.

It raises the possibility that the technology may be used for social rather than medical reasons, he says. And modifying a gene to prevent a disease runs the risk of making someone prone to another disorder.

Lord Winston was speaking ahead of the last of his programmes in the BBC television series Superhuman, which explores the issue.

Pros and cons

Lord Winston said: "Over the last 20 years, progress has been made in making transgenic animals.

"Those are animals that have new genes injected into the embryo, which then allows us to study the action of those genes.

"Within a few years, it will be possible to genetically modify large animals, perhaps for transplantation, and eventually, I think, people.

"It raises very big issues. The advantages could be that you could eradicate very serious diseases."

Genetic quirk

One potential candidate is the inherited blood disorder beta-thalassaemia. In countries like Sardinia, one in eight people are carriers of the disorder.

People with beta-thalassaemia need regular blood transfusions because their bodies cannot make normal red blood cells. If the disease is left untreated, it causes bone deformation, multiple illnesses and early death.

But, by a genetic quirk, the disorder also protects people against malaria.

Lord Winston says that though it may be possible to alter the gene that causes beta-thalassaemia, this could introduce other genetic changes that might be detrimental.

Unpredictable technology

Animal studies have shown that inserting genes into cells is unpredictable and irreversible. But the technology is becoming more efficient.

Lord Winston told the BBC: "There are a lot of scientists who feel that it might well be possible to be completely certain about how a gene might act given that you might put the whole or part of that sequence back into the body of an animal or a person.

"Of course, you then have very serious issues because it would not just be used for disease purposes - people would want to look at enhancement."

He says these sorts of questions deserve public discussion.

"What scientists are always being accused of is not debating issues which are going to come up. I feel that this is an issue there should be public debate about."