Alzheimer's genetic susceptibility could bring fear and misunderstanding, religious sc...( ity of late onset disorder at age 70 to...)

Consider first the disease and the science. Affecting some 10 million Americans, Alzheimers begins with insidious loss of memory or other cognitive skills and often culminates in complete dependence requiring assistance with hygiene, nutrition, and supervision of all activities of daily living. Of all persons with AD only 1% have an autosomal dominant gene for early onset Alzheimers found on chromosome 14 and 21; affected families can be accurately tested for the genes.

Surprisingly, a negative test does not mean you wont get AD because there are many other factors that can cause AD. Equally important, unlike tests for early onset Alzheimers, which are very accurate, tests that indicate susceptibility to late onset AD such as the APOE test are very unclear. A negative test does not mean that you will not get ADthere are other causes of AD not related to APOE. Of all those persons who are diagnosed with AD, the APOE test does not confirm the disease, nor reduce the cost of care.

Most important, APOE is not a good predictive test. A good test clearly foretells the onset of the disorder. With todays announcement that APOE and 234 genes provide higher probability there is a closer correspondence between the presences of the susceptibility and the risk of the diseasefor those people whose have 1) family member already affected with AD and 2) who have both genes. This study does not tell us whether the probability would be as high for a person in the general population if they possess copies of both genes.

Ethical issues often go unnoticed in the rush to make the tests widely available. Susceptibility testing has greater opportunity for misunderstanding because there is no proof either that with the gene you will get the disease or that
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Contact: Brent Waters
srns@science-spirit.org
412-585-0842
Science and Religion Information Service
18-Jun-2001