Spanish hospital offers genetic test for familial Alzheimer'sBMJ 2002; 324 doi: http://dx.doi.org/10.1136/bmj.324.7352.1478/f (Published 22 June 2002) Cite this as: BMJ 2002;324:1478
A clinic in Spain is offering a genetic testing and follow up service for patients who think that they are at risk of developing early onset, familial Alzheimer's disease.
The Clinic of Barcelona Hospital offers the service to people from families considered at risk, in which three people, over two generations, have developed the disease. They test for mutations on chromosome 14, 1, and 21. If the test is positive, the patient is likely to develop the disease before the age of 60.
The fact that doctors are testing for an incurable genetic disease has caused a furore in the Spanish press, but those responsible for the genetic analysis programme—the clinic's director, Dr Rafael Blesa, and the scientist in charge, Dr José Luís Molinuevo—argue that those who are aware of their prognosis will be able to plan their lives better. And they offer the test only after the patient has been assessed as being able to deal with the information.
The families with the greatest probability of having the mutations are, according to the doctors at the clinic, those with an autosomal dominant pattern of inheritance. This generally occurs in families in which three members have been affected in two generations. “These cases represent 5% of the 400 000 people with Alzheimer's disease in Spain,” said Dr Molinuevo.
Those who have a genetic mutation, principally in chromosome 14 but also in 1 and 21, “have almost 100% probability of developing Alzheimer's disease around the same age as their currently affected relatives,” said Dr Molinuevo. In most cases of early onset Alzheimer's disease, the first symptoms of the illness can be detected between the ages of 40 and 50.
Awareness of these new developments has generated an ethical debate in Spain. Experts in bioethics have emphasised the need for confidentiality and security in the storage of information. Critics fear, however, that insurance companies will refuse cover to those with a positive test, and employers may withhold jobs. It also raises the question of whether children should ever be tested, with or without their parents' permission. Some bioethicists are opposed to people being tested for a disease for which no cure and few treatments are available, though this is already done in many countries for Huntington's disease, which is also incurable.
Dr Molinuevo does not claim that he has the answers to these questions, but he is clear that for many of his clients the anxiety of not knowing can be worse than the truth. Furthermore, he emphasises that “although there is no treatment, those involved in the programme may benefit from regular counselling and psychological support.”
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