The UK's Human Fertilisation and Embryology Authority (HFEA) has given permission to a fertility clinic to test a couple's embryos for early-onset Alzheimer's disease, a genetic condition that can manifest from the age of 35.
The Bridge Centre has been granted the licence to screen embryos for Charl and Danielle De Beer. Charl De Beer's mother developed Alzheimer's at the age of 49 and died at 64. His grandmother and two of his uncles also died of the condition, which has been passed down his mother's side of the family. While Mr De Beer does not know whether he carries the condition himself, and there is a 50 per cent chance of him doing so, he wishes to spare his children the experience of living under the threat of the illness. Mr De Beer said that his family 'has been dealing with Alzheimer's for 15 years', adding 'I am not prepared to run the risk of passing this on, and my wife has the same view'. The clinic will screen embryos to ensure that only the chromosome from Mr De Beer's father's side of the family is passed on.
Early-onset Alzheimer's is a very rare genetic condition, but the move to allow the testing of embryos to exclude those that carry the gene has provoked controversy. For one, opponents argue that genetic testing should be reserved for conditions that are fatal in early life, and argue that early-onset Alzheimer's usually does not affect carriers until the age of 45. 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'.
Other opponents argue that such genetic testing leads to the destruction of healthy embryos. During the PGD process, there is a chance that one in four unaffected embryos will be discarded. Dr Alan Thornhill, scientific director at The Bridge Centre, argues that this happens in nature, and in ordinary IVF anyway. Further objections have been heard from opponents who believe that if couples are allowed to test for conditions such as early-onset Alzheimer's, a slippery slope will soon permit them to select embryos on the basis of intelligence, hair colour or sporting ability. However, Dr Thornhill argued that the process the De Beers were undergoing was emotionally and physically difficult, and thought that it was something that anyone would be highly unlikely to undergo except in cases of preventing serious and life threatening diseases.
The HFEA has classified early-onset Alzheimer's as a serious genetic condition, affecting carriers from the age of 35. In determining whether it was appropriate for the screening technique to be applied to the condition, the HFEA took expert scientific advice, looking at eight factors including the degree of suffering and speed of degeneration associated with the condition.