Early-onset Alzheimer's disease
Familial Alzheimer's disease (FAD or EOFAD for early onset) is an inherited and uncommon form of AD.
[medical citation needed] 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.
Familial AD is inherited in an autosomal dominant fashion, identified by genetics and other characteristics such as the age of onset.
The gene contains 14 exons, and the coding portion is estimated at 60 kb, as reported by Rogaev (1997)[9] and Del-Favero (1999).
[14] A subsequent study by Kovacs (1996)[15] showed that PS1 and PS2 proteins are expressed in similar amounts, and in the same organelles as each other, in mammalian neuronal cells.
This phenotype may be explained by a study by Tomita (1997)[17] suggesting that the Asn141Ile mutation alters APP metabolism causing an increased rate of protein deposition into plaques.
Mutations to the amyloid beta A4 precursor protein (APP) located on the long arm of chromosome 21 (21q21.3) cause familial Alzheimer disease.
[7] Further research into molecules like miR-212-3p might shed new light on potential therapeutic approaches for Alzheimer's disease, possibly alongside interventions targeted at APP.
However, recent research suggests that there are multiple modifiable and nonmodifiable risk factors for young onset dementia.
The major molecules involved in these pathways include glial cells (specifically astrocytes and microglia), beta-amyloid, and proinflammatory compounds.
β-amyloid is "stickier" than any other fragment produced from cut-up APP, so it starts an accumulation process in the brain, which is due to various genetic and biochemical abnormalities.
The presence of β-amyloid plaques in the brain causes the body to recruit and activate microglial cells and astrocytes.
[34] Following cleavage by β-secretase, APP is cleaved by a membrane-bound protein complex called γ-secretase to generate Aβ.
These guarantee onset of early-onset familial Alzheimer disease and all occur in the region of the APP gene that encodes the Aβ domain.
[medical citation needed] The atypical lifecourse timing of early-onset Alzheimer's means that it presents distinctive impacts upon experience.
[38] With some jobs, a mistake may have devastating consequences on a large number of people, and cases have been reported in which a person with early-onset Alzheimer's who is unaware of their condition has caused distress.
[44] While early-onset familial AD is estimated to account for only 1% of total Alzheimer's disease,[3] it has presented a useful model in studying various aspects of the disorder.
