Currently, apoe testing is used primarily in research settings to identify study participants who may have an increased risk of developing alzheimer s. Alzheimers disease fact sheet national institute on aging. Apolipoprotein e and sex risk factors for alzheimer disease. The most common form of the disease, called lateonset alzheimer disease, usually starts after age 60. Having one copy of the e4 variant of the apoe gene apoe e4 is associated with increased risk and earlier onset age of alzheimer disease dementia, and the 1%2% of the population who carry two copies of this variant apoe. How is apolipoprotein e apoe related to alzheimer s disease. Lateonset ad is the more common form of the disease manifested after the. But another gene called apoe can influence your risk for the more common lateonset type of alzheimer. Apolipoprotein e apoe is a major cholesterol carrier that supports lipid transport and injury repair in the brain. A blood test can identify which apoe alleles a person has, but results cannot predict who will or will not develop alzheimer s disease. Alzheimer disease and mci risk factors were calculated for men and women between ages 55 and 85 years for each apoe genotype. Polymorphism in the apolipoprotein e apoe gene is a major genetic risk determinant of lateonset alzheimer disease ad, with the apoe. Back in the 1990s, a major susceptibility gene was discovered for alzheimer s, called apoe4.
Apoe genotyping may be used as an aid in the diagnosis of probable late onset alzheimer disease. The e4 version of the apoe gene increases an individuals risk for developing lateonset alzheimer disease. About this report 2018 alzheimer s disease facts and figures is a statistical resource for u. Apolipoprotein e apoe is a protein involved in the metabolism of fats in the body. Apoe polymorphic alleles are the main genetic determinants of alzheimer disease ad risk. The fourth gene, apoe e4 on chromosome 19, is linked to a greater risk of susceptibility for developing lateonset alzheimers. Apolipoprotein e, known commonly as apoe, is a gene associated with varying risk of developing alzheimer. This suggests that the processes by which apoe genotype mediates dementia risk are operative well in advance. Although apoe4 is a genetic risk factor for lateonset alzheimer s disease, its effects may be different depending on whether you are a man or a woman. The challenge with testing is that many people who have apoe. A genetic linkage study using affected relative pairs, predominantly siblings. Apoe genotyping supplies supplementary information for the clinical diagnosis of alzheimer s disease. Apoe and cholesterol homeostasis in alzheimers disease. Apoe genotype and cognitive decline in a middleaged.
Apoe genotyping, alzheimer disease lab tests online. Apolipoprotein e and alzheimer disease the journal of lipid. This effect is additive in that one copy of e4 e2e4 or e3e4 carries. Dissecting the role of amerindian genetic ancestry and. Pdf apolipoprotein e apoe is a major cholesterol carrier that supports lipid. The three common forms of the gene for this protein are apoe2, apoe3, and apoe4. Alzheimer s disease ad is the most common neurodegenerative disease.
In early 1993, apoe4 was identified as a genetic risk factor for alzheimer. Apoe e4 has been associated with an increased risk of late onset alzheimer disease ad, that is ad that develops after the age of 65. Food and drug administration fda to treat cutaneous tcell lymphoma 117120, the offlabel usage of. The gene for apolipoprotein e apoe comes in three varieties alleles. Holtzman1, joachim herz2, and guojun bu3 1department of neurology, alzheimer s disease. Genetics of alzheimers disease stanford university. The growing body of evidence indicating the heterogeneity of alzheimer s disease ad, coupled with disappointing clinical studies directed at a fitforall therapy, suggest that the. If we have one apoe4 gene, either from our mom or dad, like about 15 percent of the u. Apoe e4 has been associated with an increased risk of alzheimer disease that develops after the age of 65. Alzheimer disease is a degenerative disease of the brain that causes dementia. Working group iwg and the american alzheimers association on the preclinical. Nihfunded research provides new clues on how apoe4 affects alzheimer s risk destructive enzymes shown in green become more active and weaken the bloodbrain barrier in mice that are genetically engineered to produce only human apoe4 right, rather than mouse apoe.
Alzheimer disease ad is the leading cause of dementia in the elderly and occurs in all ethnic and racial groups. Background and context for interpretating the data are contained in. It is implicated in alzheimer s disease and cardiovascular disease apoe belongs to a family of fatbinding proteins. Alzheimerdemenz oder demenz vom alzheimertyp ist eine schwere. Alzheimer s disease ad is the most common form of dementia in the elderly and currently affects more that 5 million americans. Apolipoprotein e as a therapeutic target in alzheimers disease. Pdf apolipoprotein e apoe plays a crucial role in the homeostatic control of lipids in both the periphery and the central nervous system cns. Scientists have found several genes that increase the risk of developing alzheimers disease a form of dementia one of those is the apoe gene, which tells the body how to make a protein called apolipoprotein e apoe. Apolipoprotein e plays an essential role in lipid metabolism, and the apoe gene has been involved in the neuronal degeneration that occurs in alzheimer disease. Overview of alzheimer s disease 2 types of alzheimer s disease o earlyonset ad occurs in people age 30 to 60 5% of total ad mostly inherited, known as familial alzheimer s disease fad single. Nihfunded research provides new clues on how apoe4. Apolipoprotein e apoe is a cholesterol transport protein strongly implicated in risk for agerelated neurodegenerative disorders, especially alzheimer s disease ad. Alzheimers disease is currently ranked as the sixth leading cause of death in the united states, but recent estimates indicate that the disorder may rank third, just behind heart disease and cancer, as a cause of death for older people alzheimer. Alzheimer disease and the apoe gene alzheimer disease ad is a common type of dementia.
Normal biology and roles in alzheimer disease david m. In addition, testing for apoe and interpreting the results is the first step to allow your doctor to create a tailored program for you to help prevent the onset of alzheimer. Lateonset ad is caused by a combination of genetic, environmental, and lifestyle factors. Apoe and cholesterol homeostasis in alzheimers disease vale. The apoe gene fact sheet genes contain the information to make all the proteins our body needs. View enhanced pdf access article on wiley online library html view. When you get tested and know whether you have the apoe.
This effect is additive in that one copy of e4 e2e4 or e3e4 carries some increased risk and two copies of e4 e4e4 are associated with even more of a risk of developing ad. Alzheimers disease progresses through distinct stages mild moderate severe memory loss language problems mood swings personality changes diminished judgment behavioral, personality changes. We used the alzheimer sdisease neuroimaging initiative adni database to examine the influence of apoe. The apolipoprotein e gene, attention, and brain function pdf. The best characterized apoe associated risk for ad is due to one of three apoe. Apoe genotype results are e2e2, e2e3, e2e4, e3e3, e3,e4, or e4e4. Ageadjusted odds ratios are listed in table 2 and shown in figure 1 as a function of age for the apoe.
In short, testing for the presence of the apoe 4 variant is the best way to understand your risk of developing alzheimer s. But another gene called apoe can influence your risk for the more common lateonset type of alzheimer s. Since bexarotene is a drug already approved by the u. Apoe4 and age at onset of alzheimers disease neurology. Recent data demonstrate that ad pathological changes occur decades before clinical symptoms, raising questions about the precise onset of the disease. Apoe is a protein which, in the blood, helps carry cholesterol and fat. Helping you prevent cognitive decline apoe, the gene that indicates susceptibility to cognitive decline such as alzheimer s, is a scary topic. While a quarter of alzheimer s patients have a strong family history of the disease, only 1% directly inherit a gene mutation that causes earlyonset alzheimer s, also known as familial alzheimer s disease fad. Currently, apoe testing is used primarily in research settings to identify study participants who may have an increased risk of developing alzheimer.
973 1505 136 467 1194 72 549 131 1049 440 1077 1018 317 151 788 18 1354 54 177 361 433 1337 350 1427 1105 803 353 662 834 926 926 171 557