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GTR Home > Conditions/Phenotypes > Alzheimer disease

Summary

Alzheimer's disease is a degenerative disease of the brain that causes dementia, which is a gradual loss of memory, judgment, and ability to function. This disorder usually appears in people older than age 65, but less common forms of the disease appear earlier in adulthood.\n\nMemory loss is the most common sign of Alzheimer's disease. Forgetfulness may be subtle at first, but the loss of memory worsens over time until it interferes with most aspects of daily living. Even in familiar settings, a person with Alzheimer's disease may get lost or become confused. Routine tasks such as preparing meals, doing laundry, and performing other household chores can be challenging. Additionally, it may become difficult to recognize people and name objects. Affected people increasingly require help with dressing, eating, and personal care.\n\nAs the disorder progresses, some people with Alzheimer's disease experience personality and behavioral changes and have trouble interacting in a socially appropriate manner. Other common symptoms include agitation, restlessness, withdrawal, and loss of language skills. People with Alzheimer's disease usually require total care during the advanced stages of the disease.\n\nIndividuals with Alzheimer's disease usually survive 8 to 10 years after the appearance of symptoms, but the course of the disease can range from 1 to 25 years. Survival is usually shorter in individuals diagnosed after age 80 than in those diagnosed at a younger age. In Alzheimer's disease, death usually results from pneumonia, malnutrition, or general body wasting (inanition).\n\nAlzheimer's disease can be classified as early-onset or late-onset. The signs and symptoms of the early-onset form appear between a person's thirties and mid-sixties, while the late-onset form appears during or after a person's mid-sixties. The early-onset form of Alzheimer's disease is much less common than the late-onset form, accounting for less than 10 percent of all cases of Alzheimer's disease. [from MedlinePlus Genetics]

Genes See tests for all associated and related genes

  • Also known as: AAA, ABETA, ABPP, AD1, APPI, CTFgamma, CVAP, PN-II, PN2, alpha-sAPP, preA4, APP
    Summary: amyloid beta precursor protein

Therapeutic recommendations

From Medical Genetics Summaries

This section contains excerpted1information on gene-based dosing recommendations. Neither this section nor other parts of this review contain the complete recommendations from the sources.

2023 Statement from the US Food and Drug Administration (FDA):

Patients who are apolipoprotein E ε4 (ApoE ε4) homozygotes (approximately 15% of Alzheimer’s disease patients) treated with this class of medications, including [lecanemab], have a higher incidence of ARIA, including symptomatic, serious, and severe radiographic ARIA, compared to heterozygotes and noncarriers. Testing for ApoE ε4 status should be performed prior to initiation of treatment to inform the risk of developing ARIA. Prior to testing, prescribers should discuss with patients the risk of ARIA across genotypes and the implications of genetic testing results. Prescribers should inform patients that if genotype testing is not performed they can still be treated with lecanemab; however, it cannot be determined if they are ApoE ε4 homozygotes and at higher risk for ARIA… Consider the benefit of lecanemab for the treatment of Alzheimer’s disease and potential risk of serious adverse events associated with ARIA when decided to initiate treatment with lecanemab.

Please review the complete therapeutic recommendations that are located here: (1).

1 The FDA labels specific drug formulations. We have substituted the generic names for any drug labels in this excerpt. The FDA may not have labeled all formulations containing the generic drug. Certain terms, genes, and genetic variants may be corrected in accordance with nomenclature standards, where necessary. We have given the full name of abbreviations, shown in square brackets, where necessary.

IMPORTANT NOTE: NIH does not independently verify information submitted to the GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in the GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.