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Alzheimer disease 4(AD4)

MedGen UID:
376072
Concept ID:
C1847200
Disease or Syndrome
Synonyms: AD4; Alzheimer disease familial type 4; Alzheimer Disease Risk Factor (APOE Genotype)
 
Genes (locations): APOE (19q13.32); PSEN2 (1q42.13)
 
Monarch Initiative: MONDO:0011743
OMIM®: 606889

Definition

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.

Memory 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.

As 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.

Individuals 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).

Alzheimer'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]

Clinical features

From HPO
Alzheimer disease
MedGen UID:
1853
Concept ID:
C0002395
Disease or Syndrome
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.
Apraxia
MedGen UID:
8166
Concept ID:
C0003635
Mental or Behavioral Dysfunction
A defect in the understanding of complex motor commands and in the execution of certain learned movements, i.e., deficits in the cognitive components of learned movements.
Neurofibrillary tangles
MedGen UID:
39273
Concept ID:
C0085400
Finding
Pathological protein aggregates formed by hyperphosphorylation of a microtubule-associated protein known as tau, causing it to aggregate in an insoluble form.
Memory impairment
MedGen UID:
68579
Concept ID:
C0233794
Mental or Behavioral Dysfunction
An impairment of memory as manifested by a reduced ability to remember things such as dates and names, and increased forgetfulness.
Senile plaques
MedGen UID:
83079
Concept ID:
C0333463
Acquired Abnormality
Senile plaques are extracellular deposits of amyloid in the gray matter of the brain.
Cognitive impairment
MedGen UID:
90932
Concept ID:
C0338656
Mental or Behavioral Dysfunction
Abnormal cognition is characterized by deficits in thinking, reasoning, or remembering.
Dementia
MedGen UID:
99229
Concept ID:
C0497327
Mental or Behavioral Dysfunction
A loss of global cognitive ability of sufficient amount to interfere with normal social or occupational function. Dementia represents a loss of previously present cognitive abilities, generally in adults, and can affect memory, thinking, language, judgment, and behavior.
Sleep-wake cycle disturbance
MedGen UID:
371548
Concept ID:
C1833362
Finding
Any abnormality of an individual's circadian rhythm that affects the timing of sleeping and being awake is referred to as a sleep-wake disorder.
Parietal hypometabolism in FDG PET
MedGen UID:
868400
Concept ID:
C4022794
Finding
Reduced uptake of [18F]-fluorodeoxyglucose (FDG) in the parietal cortex as measured by positron emission tomography (PET) brain scan.
Cerebral amyloid angiopathy
MedGen UID:
38998
Concept ID:
C0085220
Disease or Syndrome
Hereditary cerebral amyloid angiopathy is a condition characterized by an abnormal buildup of protein clumps called amyloid deposits in the blood vessels in the brain, causing vascular disease (angiopathy). People with hereditary cerebral amyloid angiopathy often have progressive loss of intellectual function (dementia), stroke, and other neurological problems starting in mid-adulthood. Due to neurological decline, this condition is typically fatal in one's sixties, although there is variation depending on the severity of the signs and symptoms. Most affected individuals die within a decade after signs and symptoms first appear, although some people with the disease have survived longer.\n\nThere are many different types of hereditary cerebral amyloid angiopathy. The different types are distinguished by their genetic cause, which determines whether areas of the brain other than blood vessels are affected, and the signs and symptoms that occur. The various types of hereditary cerebral amyloid angiopathy are named after the regions where they were first diagnosed.\n\nThe Dutch type of hereditary cerebral amyloid angiopathy is the most common form. Stroke is frequently the first sign of the Dutch type and is fatal in about one third of people who have this condition. Survivors often develop dementia and have recurrent strokes. About half of individuals with the Dutch type who have one or more strokes will have recurrent seizures (epilepsy).\n\nPeople with the Flemish and Italian types of hereditary cerebral amyloid angiopathy are prone to recurrent strokes and dementia. Individuals with the Piedmont type may have one or more strokes and typically experience impaired movements, numbness or tingling (paresthesias), confusion, or dementia.\n\nThe first sign of the Icelandic type of hereditary cerebral amyloid angiopathy is typically a stroke followed by dementia. Strokes associated with the Icelandic type usually occur earlier than the other types, with individuals typically experiencing their first stroke in their twenties or thirties.\n\nTwo types of hereditary cerebral amyloid angiopathy, known as familial British dementia and familial Danish dementia, are characterized by dementia and movement problems. Strokes are uncommon in these types. People with the Danish type also have clouding of the lens of the eyes (cataracts) and deafness.\n\nStrokes are rare in people with the Arctic type of hereditary cerebral amyloid angiopathy, in which the first sign is usually memory loss that then progresses to severe dementia. Strokes are also uncommon in individuals with the Iowa type. This type is characterized by memory loss, problems with vocabulary and the production of speech, personality changes, and involuntary muscle twitches (myoclonus).

Recent clinical studies

Etiology

Gawish HM, Mohamed KA, Youssef HMK, Elmenawi KA, Karkour AM, Delev D, Abdelnaby R
World Neurosurg 2023 Jul;175:e174-e200. Epub 2023 Mar 15 doi: 10.1016/j.wneu.2023.03.047. PMID: 36924888
Beaudin AE, McCreary CR, Mazerolle EL, Gee M, Sharma B, Subotic A, Zwiers AM, Cox E, Nelles K, Charlton A, Frayne R, Ismail Z, Beaulieu C, Jickling GC, Camicioli RM, Pike GB, Smith EE
Neurology 2022 Apr 26;98(17):e1716-e1728. Epub 2022 Feb 24 doi: 10.1212/WNL.0000000000200136. PMID: 35210294Free PMC Article
Kojima G, Taniguchi Y, Iliffe S, Walters K
J Am Med Dir Assoc 2016 Oct 1;17(10):881-8. Epub 2016 Jun 17 doi: 10.1016/j.jamda.2016.05.013. PMID: 27324809
Carmeliet G, Hauman R, Dom R, David G, Fryns JP, Van den Berghe H, Cassiman JJ
Mech Ageing Dev 1990 Mar 31;53(1):17-33. doi: 10.1016/0047-6374(90)90031-a. PMID: 2139155

Diagnosis

Gawish HM, Mohamed KA, Youssef HMK, Elmenawi KA, Karkour AM, Delev D, Abdelnaby R
World Neurosurg 2023 Jul;175:e174-e200. Epub 2023 Mar 15 doi: 10.1016/j.wneu.2023.03.047. PMID: 36924888
Kojima G, Taniguchi Y, Iliffe S, Walters K
J Am Med Dir Assoc 2016 Oct 1;17(10):881-8. Epub 2016 Jun 17 doi: 10.1016/j.jamda.2016.05.013. PMID: 27324809

Therapy

Kojima G, Taniguchi Y, Iliffe S, Walters K
J Am Med Dir Assoc 2016 Oct 1;17(10):881-8. Epub 2016 Jun 17 doi: 10.1016/j.jamda.2016.05.013. PMID: 27324809

Prognosis

Gawish HM, Mohamed KA, Youssef HMK, Elmenawi KA, Karkour AM, Delev D, Abdelnaby R
World Neurosurg 2023 Jul;175:e174-e200. Epub 2023 Mar 15 doi: 10.1016/j.wneu.2023.03.047. PMID: 36924888
Kojima G, Taniguchi Y, Iliffe S, Walters K
J Am Med Dir Assoc 2016 Oct 1;17(10):881-8. Epub 2016 Jun 17 doi: 10.1016/j.jamda.2016.05.013. PMID: 27324809

Clinical prediction guides

Gawish HM, Mohamed KA, Youssef HMK, Elmenawi KA, Karkour AM, Delev D, Abdelnaby R
World Neurosurg 2023 Jul;175:e174-e200. Epub 2023 Mar 15 doi: 10.1016/j.wneu.2023.03.047. PMID: 36924888
Kojima G, Taniguchi Y, Iliffe S, Walters K
J Am Med Dir Assoc 2016 Oct 1;17(10):881-8. Epub 2016 Jun 17 doi: 10.1016/j.jamda.2016.05.013. PMID: 27324809
Carmeliet G, Hauman R, Dom R, David G, Fryns JP, Van den Berghe H, Cassiman JJ
Mech Ageing Dev 1990 Mar 31;53(1):17-33. doi: 10.1016/0047-6374(90)90031-a. PMID: 2139155

Recent systematic reviews

Kojima G, Taniguchi Y, Iliffe S, Walters K
J Am Med Dir Assoc 2016 Oct 1;17(10):881-8. Epub 2016 Jun 17 doi: 10.1016/j.jamda.2016.05.013. PMID: 27324809

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