How Is It Used
APOE genotyping is sometimes used as an added test to help in the diagnosis of probable late onset Alzheimer disease in symptomatic adults. However, the association of the e4 allele with late onset AD does not mean that it causes AD, only that more people with late onset AD have e4 alleles compared to similar aged peers without late onset AD. For this reason, APOE genotyping is referred to as susceptibility or risk factor testing since it indicates whether there is an increased risk of AD but is not specifically diagnostic of AD. For example, if a person has dementia, the presence of APOE;e4 may increase the likelihood that the dementia is due to AD but does not prove that it is.
There are no clear-cut tests to diagnose Alzheimer disease during life. Healthcare practitioners can, however, make a reasonably accurate clinical diagnosis of AD by ruling out other potential causes of dementia and checking for a genetic predisposition to AD with APOE genotyping as supplemental information in conjunction with tau protein and beta amyloid;testing.
Information About Genetic Testing
Having a test to look for a faulty gene that causes dementia is only appropriate for a very small number of people. This is because inherited dementia is rare.
If you are worried that you have a strong history family of early-onset Alzheimers disease or frontotemporal dementia, you can speak to your doctor about this.
Not all gene mutations that cause dementia have been identified, meaning that some families may have many affected members, but no mutation can be found. Therefore, a negative test result cannot always rule out a genetic cause of a disease.
If a test is appropriate, your doctor should be able to refer you to a genetic counsellor or specialist. This could be a cognitive neurologist or memory clinic psychiatrist. They will discuss with you the pros and cons of taking a test and what will be involved. They will also tell you where the results will be kept, who they will be shared with, and what the next steps would be. For people found to have a genetic mutation that causes dementia, these discussions will also cover the options available if you are considering starting a family.
To find out more about genetic testing and what support is available you can visit www.raredementiasupport.org or call 020 3325 0828. Leave a message and you will be referred to the most appropriate team member.
What Is The Clock Test For Dementia
The clock test is a non-verbal screening tool that may be used as part of the assessment for dementia, Alzheimers, and other neurological problems. The clock test screens for cognitive impairment. The individual being screened is asked to draw a clock with the hour and minute hands pointing to a specific time. Research has shown that six potential errors in the clock testthe wrong time, no hands, missing numbers, number substitutions, repetition, and refusalcould be indicative of dementia.
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Genetic Testing For Alzheimer’s
By;Dr. Brandon Colby;MD, a Personalized Preventive;Medicine specialist and expert in clinical;genomics.
When we think of the possible ailments that we could develop during our senior years, Alzheimers disease is probably one of the options that we all fear the;most.
Alzheimers disease is the most common type of;dementia.1 Dementia isnt a single, specific disease instead, its a term used to describe a combination of symptoms that includes the progressive loss of different cognitive functions, such as memory, orientation, language, and attention. As a result, Alzheimers disease and other types of dementia have a significant impact on a persons everyday life, and in the lives of their loved ones and;caregivers.
Similarly to other types of dementia, Alzheimers disease leads to progressive impairment and different symptoms, which;include:
- Memory loss
Once upon a time but really, up until fairly recently it was widely believed that dementia was just a normal part of aging and that we all developed it if we lived to be old enough. In fact, dementia was such a normal part of human aging that for many centuries, doctors didnt even try to prevent nor treat;dementia.;
Thankfully, there are many different things we can all do to assess our risk of developing Alzheimers disease, and also to keep our brains healthy as we get older. After all aging is a privilege, and we owe it to ourselves to do everything we can to stay;healthy.
Consideration Of Other Risk Factors
Harboring the ApoE4 allele is the most important genetic risk factor for late-onset Alzheimers, and knowing ones E4 allele status certainly could be transforming, particularly in terms of preventative, beneficial lifestyle changes individuals may undergo.
However, there are important considerations to take into account before testing to help mitigate stress and anxiety associated with a positive E4 test. Other experts and I suggest that people start by becoming well-informed about the basics of ApoE4. If testing is carried out and a higher risk is revealed, it is critically important those individuals obtain genetic counseling and be actively assisted about how to proceed.
Whether you carry the ApoE4 gene or not, many other risk factors are thought to contribute to Alzheimers, not just genes and old age. What you eat, how much you exercise, formal education, smoking, how mentally active you remain and other factors have all been implicated.
Ultimately, the choice of whether to get a genetic test remains a personal one all the more reason its important to be informed about the pros and cons of Alzheimers screening and what doctors know about your risk for the disease and whether viable treatment options are available.
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What Is The Apoe Gene
The APOE gene plays different roles in our brain function; among other things, it produces a protein called apolipoprotein E, which helps eliminate deposits of a substance called amyloid-beta peptide that can accumulate and form amyloid plaques. These amyloid plaques hinder brain function and eventually lead to Alzheimers;disease.
This gene also aids in the maintenance of a normal brain function synaptic plasticity, which is the process through which our brain cells establish synapses to communicate with each other. For these reasons, the APOE gene and its alleles play a very important role in the development of Alzheimers;disease.3
The genetic variants that can affect your risk of developing late-onset Alzheimers disease;are:
- APOE2: this is the least common allele of this gene, and it enables the APOE gene to synthesize larger amounts of apolipoprotein E, thus protecting your brain against;Alzheimers.;
- APOE3: this is the neutral allele of the APOE gene since it doesnt seem to affect the production of apolipoprotein E. As a result, this variant neither decreases nor increases your susceptibility to Alzheimers. However, research has found that APOE3 in combination with specific variants in other genes could lead to an increased risk of Alzheimers disease for some;people.
- APOE4: finally, the APOE4 allele hinders the production of apolipoprotein E, which could put you at an increased risk of developing the;disease.
- ABCA7 gene
- SORL1 gene
What Is Dementia And What Causes It
Dementia is a syndrome that causes a person to develop difficulty and problems with their memory or their ability to think. Unlike the normal changes that happen in a persons memory and thinking over time, dementia affects someones ability to function in their daily life activities and their normal routine .There are different causes of dementia. These causes are typically underlying neurological conditions . One common cause of dementia is Alzheimers disease. Other causes include diseases that impact brain blood vessels. For example, strokes may cause what is commonly termed Vascular Dementia. Some causes include Lewy Body Disease and Parkinsons disease.
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As Part Of Our Livetalk Series Being Patient Spoke With Jessica Langbaum Co
Certain genes like ApoE that play an important role in the disease. ApoEs genetic variant, known as ApoE4, is the strongest genetic risk factor for developing Alzheimers in later life.;Genetic tests by mail, like 23andMe and AncestryDNA, make it easy to learn about ones ApoE status and to learn that one may have a much higher likelihood of developing Alzheimers in their lifetime. But just because a person carries the ApoE4 variant doesnt mean that their fate is sealed: Alzheimers is a complicated disease, and genetics is one among many factors, from lifestyle and environmental factors to preexisting health conditions, that influence peoples risk.
Being Patient sat down with Jessica Langbaum, co-director of the Alzheimers Prevention Initiative at the Banner Alzheimers Institute, to discuss the complex role of genetics in Alzheimers, asking: Should people seek genetic testing for Alzheimers? And if they do, how can they ensure they are prepared for what they find?
Genetic Testing For Alzheimers Has Emotional Risk
August 18, 2020 â Twelve years ago, Jamie Tyrone volunteered to participate in a clinical trial. The researchers wanted to know whether learning your genetic risk for developing some 20 or so different diseases, through a direct-to-consumer genetic test, would prompt you to take up a healthier lifestyle. But Tyrone wanted to get something else out of the study.
The San Diego-based retired nurse, now 59, had been living with mysterious progressive neurological problems for about 15 years. The debilitating weakness and fatigue had pushed her into early retirement. Sometimes she needed a scooter to get around the one-story ranch she and her husband bought to accommodate her increasing physical challenges. But doctors had never made a definitive diagnosis. While brain scans ruled out multiple sclerosis, this clinical trial would tell her if she had a gene that predisposed her to the condition.
So focused on learning her genetic risk for MS, Tyrone didnât give any thought to the other diseases sheâd learn her risk for, including Alzheimerâs disease.
Tyrone had two copies of the e4 variant of the APOE gene one inherited from her mother and one from her father. Someone who has one copy of e4 may be three times as likely to develop Alzheimerâs disease as someone who doesnât have it. Two copies can make you up to 12 times more likely to develop the disease. Tyrone was devastated.
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Alzheimers / Dementia Testing Alternatives
Despite the lack of an FDA-approved blood test, families who suspect their loved one may have Alzheimers have a well-trod, if meandering, path to a diagnosis. To begin the process, there are online tests for Alzheimers that can be downloaded, printed, completed and taken to your doctor, and even some interactive tests that might provide immediate results. However, these online tests do not actually test for Alzheimers or dementia. Instead, they offer families answers to these questions: Are my concerns about my loved one justified?Is this just normal aging or is there something more going on? Officially, the tests are looking for Mild Cognitive Impairment . These tests are not definitive, but they can help a family figure out what their next step should be.
If a doctor suspects a patient may have Alzheimers, there are more definitive approaches. Brain scans and tests on extracted spinal fluid when coupled with multiple physicians consultations can make a diagnosis of Alzheimers with upwards of 90 percent accuracy. Families should expect their loved one to be evaluated by a neurologist, a psychiatrist, and very likely a psychologist as well. Since Alzheimers is so common among the elderly, a diagnosis is less about finding a condition which fits and more about eliminating other possibilities.
What Diagnosis Falls Under Alzheimer’s Disease
Alzheimers disease is a diagnosis in itself. When it is noticeable clinically and identified early on, the formal diagnosis may be Mild Cognitive Impairment due to Alzheimers disease which may later develop into a diagnosis of dementia due to Alzheimers disease.
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How Does A Doctor Test For Dementia
There is no single diagnostic test for Alzheimers disease and other causes of dementia. Dementias are diagnosed by evaluating and understanding a persons memory and thinking patterns. Doctors will consider a persons memory, grasp of language, mood states, problem-solving skills, ability to maintain focus and perform complex tasks. Evaluation may include in-office cognitive screening , physical examination, and review of labs. Labwork helps to determine whether there are vitamin deficiencies or hormonal changes at play. In some cases, evaluation may require neuropsychological testing, brain imaging , and genetic testing.
Genetic Testing For Hereditary Dementia
If you have or had a parent with Alzheimers disease, its usually not recommended that you get genetic testing.
Testing positive for the gene may not change your medical treatment. It also does not mean you will get Alzheimers. But it could create anxiety and stress and affect your quality of life.
So while genes may increase your risk, there are ways to decrease it, too. The best course of action to reduce your risk factors for cardiovascular disease, including high blood pressure, high cholesterol, and diabetes.
The Alzheimers Associations guidelines include eating a healthy diet, maintaining a healthy weight, and exercising regularly. Its also important to maintain social connections and keep your brain active by learning a new skill, finding a hobby, or taking a class.
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Can Dementia Suddenly Get Worse
The progression of dementia depends on the underlying disease. Some diseases have a rapid progression. Others progress more slowly. Any sudden change with either slow or rapid progression should be evaluated for another cause. In most cases, changes with dementia may seem like they came out of the blue when they actually may have been slowly developing in the background. The best way to prepare for changes and manage expectations is through information. Your doctor and medical team will be a valuable resource. There are a variety of educational resources that are also available through the Alzheimer’s Association.
Gene Linked To Alzheimer’s Poses A Special Threat To Women
Langbaum says volunteers get a lot of education before they learn their genetic status.
“There are family considerations, there are emotional considerations and there are insurance implications or considerations that people should think about before learning this information,” she says.
Participants in the study also talk to a genetics counselor at the University of Pennsylvania when they get their results. Half of those encounters take place over the phone and half use a video link.
One of the study’s goals is to “learn how to tell people this information about their genetic susceptibility,” Langbaum says. Researchers also hope to learn how to convey results of other risk assessments, including brain scans and tests of blood and spinal fluid, which are also part of the study.
When Rubie talks to the counselor, she learns she has a single copy of the APOE E4 gene. And she’s OK with that.
“I’m very glad to know,” she says. “It takes the mystery out of it.”
The implications for children
The process is a bit more fraught for David, 72, a retired businessman.
Before he gets his results, he thinks he’s prepared.
“I’m a big boy,” he says. “If the testing comes out to where I’m running a higher risk, I think I’m going to put a lot more emphasis on enjoying the time that I have.”
But after learning his status, David is concerned.
David, like Rubie, learned that he has a single copy of the APOE E4 gene, which means he has a modestly elevated risk of getting Alzheimer’s.
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What Is Genetic Testing
Genetic testing helps to find out if a persons genes or chromosomes may be linked to a health condition; it can also identify changes in a persons genes. The procedure can be done before a pregnancy, during a pregnancy, or later in life.;
Genetic testing is not available for every condition. It is also not usually possible unless the gene change is already known in the family. Lastly, results of the testing are not always clear. Because of these and other limitations with genetic testing, and because not all health conditions are genetic, a normal result does not guarantee that a child will be healthy.
Know What Youre Getting Into
Learning you have a gene that increases your risk for a serious disease can cause a lot of anxiety and distress. Critics of APOEe4 testing say people may not understand how the information could affect them and may regret finding out.
âIf I had had genetic counseling first, I probably wouldnât have wanted to know,â says Tyrone, who describes the depression this news caused in her book Fighting for My Life: How to Thrive in the Shadow of Alzheimerâs. The lack of support that Tyrone received after learning her APOEe4 status led her to seek help from a therapist, who diagnosed her with post-traumatic stress disorder.
People like Tyrone, who didnât know they had been tested for this gene, may be most likely to suffer psychological consequences. âThe people who are unaware that APOE was on the test come to me a bit panic stricken when they find out their result,â says Scott Weissman, a certified genetic counselor who runs Chicago Genetics.
Genetic counselors educate people on their risk for diseases, including Alzheimerâs, based on the numerous factors that figure into these conditions. After discussing their results with a counselor, Weissman says, people tend to feel better about their APOEe4 status.
âIf Iâm hearing that they will be very anxious , I tell them, âLook, you probably donât want this information,ââ Weissman says.