Related Experiment Videos
Genetic risk of Alzheimer's disease: advising relatives
M B Liddell1, S Lovestone, M J Owen
1Department of Psychological Medicine, University of Wales College of Medicine, Cardiff, UK. liddellmb@cardiff.ac.uk
Background:
Clinicians are increasingly asked by relatives of patients with Alzheimer's disease to advise on their genetic risk of developing Alzheimer's disease in later life. Many clinicians find this a difficult question to answer.
Aims:
To provide information for old age psychiatrists wishing to advise relatives of their risk of developing Alzheimer's disease.
Method:
A selective review of the key literature on the genetic epidemiology of Alzheimer's disease.
Results:
Currently a DNA diagnosis is attainable in some 70% of families with autosomal dominant Alzheimer's disease. In first-degree relatives of most cases, risk is increased some three- or four-fold relative to controls, but only one-third of this is realised in the average life span. Apolipoprotein E genotyping cannot be used as a predictive test and confers only minimal diagnostic benefit.
Conclusions:
Pedigrees with familial Alzheimer's disease should be referred to a Regional Centre for Medical Genetics. Accurate risk prediction is not possible in the vast majority of pedigrees with Alzheimer's disease, although it is possible for the psychiatrist to give a rough estimate of the risk, which can reasonably the couched in reassuring terms.