Early-onset Alzheimer's disease

Early-onset Alzheimer's disease, also called early-onset Alzheimer's, or early-onset AD, is Alzheimer's disease diagnosed before the age of 65. It is an uncommon form of Alzheimer's, accounting for only 5-10% of all Alzheimer's cases. About 13% of the cases of early-onset Alzheimer's are familial, where a genetic predisposition leads to the disease. The other incidences of early-onset Alzheimer's, however, share the same traits as the 'late-onset' form of Alzheimer's disease, and little is understood about how it starts. Early-onset Alzheimer's disease, also called early-onset Alzheimer's, or early-onset AD, is Alzheimer's disease diagnosed before the age of 65. It is an uncommon form of Alzheimer's, accounting for only 5-10% of all Alzheimer's cases. About 13% of the cases of early-onset Alzheimer's are familial, where a genetic predisposition leads to the disease. The other incidences of early-onset Alzheimer's, however, share the same traits as the 'late-onset' form of Alzheimer's disease, and little is understood about how it starts. Nonfamilial early-onset AD can develop in people who are in their 30s or 40s, but this is extremely rare. The majority of people with early-onset Alzheimer's are in their 50s or early 60s. The symptoms of the disease as a distinct nosologic entity were first identified by Emil Kraepelin, and the characteristic neuropathology was first observed by Alois Alzheimer in 1906. In this sense, the disease was co-discovered by Kraepelin and Alzheimer, who worked in Kraepelin's laboratory. Because of the overwhelming importance Kraepelin attached to finding the neuropathological basis of psychiatric disorders, Kraepelin made the decision that the disease would bear Alzheimer's name. Familial Alzheimer's disease (FAD) or early-onset familial Alzheimer's disease (EOFAD) is an uncommon form of Alzheimer's disease that usually strikes earlier in life, defined as before the age of 65 (usually between 50 and 65 years of age) and is inherited in an autosomal dominant fashion, identified by genetics and other characteristics such as the age of onset. Familial AD requires the patient to have at least one first-degree relative with a history of AD. Nonfamilial cases of AD are referred to as 'sporadic' AD, where genetic risk factors are minor or unclear. While early-onset familial AD is estimated to account for only 3.5% of total Alzheimer's disease, it has presented a useful model in studying various aspects of the disorder. Currently, the early-onset familial AD gene mutations guide the vast majority of animal model-based therapeutic discovery and development for AD. Alzheimer's disease (AD) is the most common cause of dementia and usually occurs in old age. It is invariably fatal, generally within 10 years of the first signs. Early signs of AD include unusual memory loss, particularly in remembering recent events and the names of people and things, logopenic primary progressive aphasia. As the disease progresses, the patient exhibits more serious problems, becoming subject to mood swings and unable to perform complex activities such as driving. In the latter stages, they forget how to do simple things such as brushing their hair and then require full-time care. Histologically, familial AD is practically indistinguishable from other forms of the disease. Deposits of amyloid can be seen in sections of brain tissue. This amyloid protein forms plaques and neurofibrillary tangles that progress through the brain. Very rarely, the plaque may be unique, or uncharacteristic of AD; this can happen when a mutation occurs in one of the genes that creates a functional, but malformed, protein instead of the ineffective gene products that usually result from mutations.