They do not exist but could be available in five to 10 years, the association said. Doctors fear developments in genetic therapy to cure disease might be turned to evil ends in the hands of a dictator.
Biological or chemical weapons could theoretically be targeted by addition of a gene marker to attack a specific part of the human body. The genetically engineered toxin might be sprayed into the air or added to food and water. If clusters of genes only seen in particular ethnic groups could be identified, it might be possible to devise an ethnic weapon. Vivienne Nathanson, head of science and ethics at the BMA, said: "It is clearly a very frightening scenario. We are trying to prevent new weapons being developed and distributed. We want to know whether genetic weapons are feasible and how to control or stop them."
The investigation, commissioned by the association's board of science, was announced at the BMA's annual conference in Edinburgh. It is due for completion in 12 months. Scientists expect to be able to produce the first genetically targeted drugs in five years. The drugs would repair faulty DNA within the cell and might be used to treat conditions such as diabetes and cystic fibrosis. Dr Nathanson said: "No one has been able to tell me why, if we can produce genetically targeted drugs with a good effect, we won't be able to produce similar drugs with a bad effect in the same time-scale."
The Human Genome Project, which is mapping the entire human genetic code, might produce enough information to allow specific genetic types to be identified. "We know the genes for hair colour, eye colour and height. If 90 per cent of the [enemy] have blue eyes, blond hair and are over six feet tall, that could be the cluster you are looking for." Certain blood types were commoner in different ethnic groups and could also be targeted, she said.
Earlier the conference called for the manufacture and supply of instruments of torture to be banned after hearing of British companies that had sold the equipment abroad.
An iron foundry in Birmingham had produced leg and arm shackles and other companies had made hi-tech torture chambers, which used low-level noise to drive victims mad, and a mass gallows for export to Saudi Arabia, the conference was told. Investigations by Amnesty International had found a number of companies exploiting legal loopholes to manufacture and export the equipment.
James Barrett, a member of the BMA council and chairman of the medical group of Amnesty International, said shackles made by the Birmingham company were deliberately designed to crush the radial nerve in the arm when tightened. "They made good profits," he said.
Sandy Macara, chairman of the BMA, said: "There is nothing good about the profits made out of this trade".
The conference called for the creation of mechanisms in every country through which doctors could report human-rights abuses and torture.
It supported the Government's ban on land mines, which was announced last May following an appeal by Diana, Princess of Wales, and said the money saved on the defence budget should be used to clear them.Reuse content