Monkeys which were genetically modified to suffer an agonising human disease have added a new twist to the controversy over animal experiments.Five rhesus macaques were created in a laboratory with the defective gene which causes Huntington's Disease, a deadly and incurable illness which usually strikes humans in middle age.
One of the IVF monkeys, now ten months old, is already suffering from involuntary spasms of the hand and face - both classic symptoms.
Of the others, two died within a day, another lived for a month and the last has yet to show any signs of the disease.
Huntington's is a hereditary condition caused by a single rogue gene which causes nerve cells in the brain to waste away.
Within ten to 15 years of the first symptoms, most patients die from pneumonia, heart failure or choking.
The monkey experiment is being held at Emory University's Yerkes National Primate Research Centre in Atlanta, Georgia.
Researchers said monkeys and other primates are more likely to help with a breakthrough cure than laboratory rats because they are much closer to humans.
They claim GM primates could be bred to combat other degenerative brain diseases such as Parkinson's and Alzheimer's.
A senior member of People for the Ethical Treatment of Animals said: "It is unconscionable. These monkeys will die a terrible death. There is no justification for it. It is morally indefensible."
© 2008 The Daily Mail