Dr Doug Brown, the Alzheimer's Society director of research and development, said people "must be given a choice about whether they would want to know, and fully understand the implications" of a test that could predict the onset of the disease.
We asked users of the ITV News Facebook page whether they would want to know in advance if they were likely to develop Alzheimer's.
- Dawn Kinsley: "One of the worst diseases going. So I would want to know, then I can get together my 'care' plan, have some 'careless' good times while I still remember and can enjoy."
- Mechelle Thomson: "Only to prepare my family so they would know what to expect. A little education could go a long way."
- Michael King: "How depressing knowing that you're going to get it in advance and being able to do little about it. I'd rather not know."