Test to End Genetically Inherited Disorders

SCIENTISTS are on the verge of eradicating genetically inherited diseases after the development of a test to spot haemophilia A in IVF embryos.

The technique was created by scientists at Hammersmith and Queen Charlotte’s Hospital and a couple have gone through the IVF procedure for the first time in order to avoid having a child with the blood disorder.

Steve and Debbie Hunter have a son Ben, ten, with haemophilia and Mrs Hunter’s father Bob, also a haemophiliac, died as a result of being given HIV-infected blood products.

The couple were able to have a child normally, but chose IVF so that scientists could test the four to ten embryos normally produced by the process and then implant two lacking the gene that causes haemophilia A.

In the Hunters’ case, an embryo clear of the condition was implanted along with a female embryo, which was a carrier. The resulting child, Grace, is now 12 weeks old.

This method of screening out the massive range of genetically inherited diseases is growing rapidly – there are tests for cystic fibrosis, Huntingdon’s chorea and a gene linked with bowel cancer in early life – and would enable families with histories of the conditions to have unaffected children.

Mrs Hunter, from Alton in Hampshire, said she was unhappy with the idea of terminating a pregnancy because the baby had haemophilia.

“Abortion would never have been an option. I love Ben to bits and I would not change him for the world,” she said.

IVF involves several courses of treatment. “It sounds easy but it’s not, it’s very difficult, emotionally and physically,” Mrs Hunter said.

“But Grace is fine, she’s absolutely wonderful and well worth it. The technology is amazing. They did try to explain it to me, but it’s well over my head.”

Professor Ted Tuddenham, who developed the pre- implantation genetic diagnosis (PGD) technique for haemophilia A with colleagues at the Clinical Sciences Centre in Hammersmith, said they were “very pleased” at the success of their work. Three couples with a family history of haemophilia are awaiting treatment.

While the Hunters were a “young, fertile couple” they were treated free on the NHS. Prof Tuddenham said the technique would be made available free to all 2,300 couples with a family history of haemophilia A, while work was continuing on a test for haemophilia B.

“The Institute of Reproductive and Developmental Biology … is going to offer this as a service through the NHS,” he said.

“The costs of haemophilia are very, very substantial – roughly GBP 10,000 a year for [blood products] factor eight or factor nine replacement alone – so, on an overall health economics basis, and not just the parents wanting a normal, healthy child, it makes sense.”

He added that the 1 per cent of families in Britain at risk of having a child with a severe, genetically inherited diseases could be helped by the same method once a PGD test was developed for their particular condition. “There are 12,000 defined genetic disorders in humans. Not all of them are severe enough to warrant this approach, but more than half of them are,” he said.

However, this would not eradicate all genetic diseases as some are not inherited but result from mutations that happen naturally at conception.

Simon Morris, the services development manager for the Haemophilia Society UK, welcomed Prof Tuddenham’s research, saying it provided a choice for parents with or carrying haemophilia.

However, he expressed concern that some may be pressured into having a child in this way. “It’s a potential worry that social pressure, economic, political, moral pressure will be to go through this and that’s something we wouldn’t want to see,” he said.