[Down's syndrome and dementia]

To review the relationship between Down's syndrome and Alzheimer's disease.

Down's syndrome is the commonest autosomopathy. Its clinical features permit easy diagnosis. Control of the more severe complications, such as cardiac malformations have allowed prolonged survival. The presence of neuropathological findings similar to those in Alzheimer's disease is almost constant in the brains of patients aged over 40 years with Down's syndrome. Dementia appears in a third of these patients. In this article we comment on the diagnostic difficulties, possible risk factors and the importance of findings related to chromosome 21. We also evaluate the results of new treatments with cholinesterase inhibitors.

The study of the close relationship between Down's syndrome and Alzheimer's disease should allow us to advance understanding of both of these conditions.