Down's syndrome and dementia

Abstract

Down's syndrome is the most common genetic disorder seen in clinical practice: about 94% occurs because of non-disjunction of chromosome 21 and 3–5% because of translocation. Individuals increasingly survive to middle and old age, probably because of advances in medical treatment and improved living conditions. People with Down's syndrome have an increased risk of developing Alzheimer's disease in middle age. Within ICD–10 and DSM–IV classifications there is no consensus on the diagnosis of dementia in people with learning disability. New treatments have been licensed for use in mild to moderate Alzheimer's disease (e.g. acetylcholinesterase inhibitors and memantine). The comorbid picture of Down's syndrome and Alzheimer's disease presents a unique challenge to the clinician in both diagnosis and management.