Parents allowed to screen IVF embryo for Alzheimer's

The Human Fertilisation and Embryology Authority has approved the tests, which will allow embryos of the parents, who have a history of the disease in their family, to be screened for the genetic defect.

The screening, which will be carried out by a fertility clinic, will prevent early-onset Alzheimer's - a genetic condition which can take hold from age 35 - being passed onto the infant.

But the technique has sparked controversy - with opponents claiming it will eventually lead to the creation of "designer babies", where parents can choose eye and hair colour, athletic ability and intelligence.

Screening embryos for genes that predispose people to Alzheimer's in particular is even more controversial than other diseases because it is regarded as an illness of age.

Even early onset Alzheimer's does not affect patients until their forties and fifties.

Opponents also claim the process, called the pre-implantation genetic diagnosis (PGD), could lead to unaffected embryos being destroyed unnecessarily.

The couple involved in this case, which was given the green-light earlier this month, are Mr Charl de Beer and his wife Danielle, from London.

Specialists at the Bridge Centre fertility clinic in London will carry out IVF treatment to create the embryos.

But only those embryos that are not carrying the defective gene will be implanted.

The family history of the disease is on Mr de Beer's mother's side.

Mr de Beer's mother Patricia developed Alzheimer's at 49 and died aged 64.

His grandmother and two uncles also died prematurely from the condition.

Experts say there is a 50 per cent he is carrying the gene and a 50 per cent chance of him passing it on.

While Mr de Beer has said he does not want to know if he is carrying the disease, he and his wife, both in their early thirties, want to make sure any child is spared the condition.

At the time the clinic applied for the licence in April this year, Mr de Beer said: "My family has been dealing with Alzheimer's for 15 years.

"I am not prepared to run the risk of passing this on and my wife has the same view."

As Mr de Beer's father's side of the family is unaffected, specialists will screen embryos to ensure only the chromosome from that side is passed on.

But this process, which has previously been used in America, runs the a one in four risk that a healthy embryo will be discarded.

Dr Alan Thornhill, the scientific director at Bridge, said this happened in nature and in ordinary IVF anyway.

He added that people suffering from early-onset Alzheimer's had "only half a life worth living" so it was sensible to try and eliminate the gene that causes it.

There are at least 500,000 people with Alzheimer's in the UK.

But there are only 750 cases of early onset Alzheimer's which are caused by defective genes.

A spokesman for the Embryology Authority said: "Early onset Alzheimer's is a serious genetic condition where dementia occurs in patients from the age of 35.

"There is a high risk of the condition being passes on to any children that the carriers may have."

But an opponent of the technique, Dr David King, director of Human Genetics Alert, said: "We can confidently expect science to find a cure for Alzheimer's in the next 40 years.

"I don't believe that it is better never to have been born than to live a healthy life for 45 years and die from Alzheimer's.

"If we don't want to slide down this slippery slope, we must restrict PGD to conditions that are fatal in early life."