Early-onset Alzheimer disease: when is genetic testing appropriate?

Alzheimer disease (AD) is a neurodegenerative disease that is currently not preventable or curable. Early-onset AD can be due to mutations in several autosomal dominant genes. Clinical testing is available for presenilin 1 (PS1), which is the most common of these genes. However, many practical and ethical issues must be considered before ordering this test for patients with early-onset AD. In this paper, we present a case that demonstrates the complexities of genetic testing for early-onset AD.