New insights into genetic aspects of Alzheimer's disease. Does genetic information make a difference in clinical practice?
ABSTRACT Genetic testing sometimes offers definitive information for patients who have a family history of early-onset Alzheimer's disease that occurs before age 50 in a Mendelian pattern. However, for patients who are already symptomatic, especially those with sufficient symptoms to warrant a clinical diagnosis of Alzheimer's disease, genetic testing may not contribute a great deal of information beyond that already available from the clinical and family history. For prediction of disease onset, genetic testing can sometimes give a clear picture of disease risk, but each patient must carefully weigh the risks and benefits of having that information. For early-onset Alzheimer's disease occurring beyond age 50 or without a clear Mendelian pattern, genetic testing is unlikely to be informative. In patients who have a family history of late-onset Alzheimer's disease, while APOE's contribution to increased risk is indisputable, its potential use as a genetic test is very limited. Testing may be helpful as an adjunct to clinical diagnosis but does not obviate the need for a full workup for treatable causes. Thus, the benefit of testing may be marginal. No consensus has been reached as to the value of genetic testing for early detection of late-onset disease, but APOE testing might become important in the future if it helps to define the need for intervention or to select an optimal intervention. There is a broad consensus that APOE testing lacks sufficient predictive value to be suitable for predictive testing in asymptomatic persons.
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ABSTRACT: Genetic testing for Alzheimer disease includes genotyping for apolipoprotein E, for late-onset Alzheimer disease, and three rare autosomal dominant, early-onset forms of Alzheimer disease associated with different genes (APP, PSEN1, and PSEN2). According to researchers, patents have not impeded research in the field, nor were patents an important consideration in the quest for the genetic risk factors. Athena Diagnostics holds exclusive licenses from Duke University for three "method" patents covering apolipoprotein E genetic testing. Athena offers tests for apolipoprotein E and genes associated with early-onset, autosomal-dominant Alzheimer disease. One of those presenilin genes is patented and exclusively licensed to Athena; the other presenilin gene was patented but the patent was allowed to lapse; and one (amyloid precursor protein) is patented as a research tool. Direct-to-consumer testing is available for some Alzheimer disease-related genes, apparently without a license. Athena Diagnostics consolidated its position in the market for Alzheimer disease genetic testing by collecting exclusive rights to patents arising from university research. Duke University also used its licenses to Athena to enforce adherence to clinical guidelines, including elimination of the service from Smart Genetics, which was offering direct-to-consumer risk assessment based on apolipoprotein E genotyping.Genetics in medicine: official journal of the American College of Medical Genetics 04/2010; 12(4 Suppl):S71-82. DOI:10.1097/GIM.0b013e3181d5a68e · 3.92 Impact Factor