Are There Harms Or Limitations Of Genetic Testing
Currently no cure or effective preventive therapy is available if a gene mutation is found. A positive test result for a known early-onset familial AD family gene mutation can result in:
- Adverse psychological reaction, family issues/distress
- Confidentiality issues
- Historically, genetic testing in an asymptomatic individual may have affected their ability to obtain life, disability, critical illness, long-term care and/or extended health insurance. However, in 2017 Canada passed the Genetic Information Non-Discrimination Act that protects individuals from the use of a genetic test result to prevent them from obtaining insurance.
A negative test result for a known familial early-onset familial AD gene mutation can result in survivor guilt.
When an individual with no known familial gene mutation has genetic testing, a negative result is not a definitive answer.
For review articles on AD see Alonso Vilatela ME et al., Genetics of Alzheimers disease. Arch Med Res. 2012 43: 622-31 and Goldman JS et al., Genetic counseling and testing for Alzheimer disease: Joint practice guidelines of the American College of Medical Genetics and the National Society of Genetic Counselors. Genet Med 2011 13: 597-605.
Other AD resources:
Getting A Genetic Test For Familial Alzheimers Disease At 25
This blog is a cross-post with The Huffington Post.
When people hear the word Alzheimers, many envision an elderly person shut away in the depths of a care home. As a 25-year-old, I was all too aware that young people assume that its a natural part of ageing, and nothing for them to worry about yet. But its not, its a brain disease that strips everything away from the individual and it doesnt just affect the elderly.
For an unfortunate few of us its something that will have a huge impact on our lives, from the second were born to the moment we die.
Around the world there are only a few hundred families who have been identified as having a rare, inherited form of the disease. Familial Alzheimers accounts for less than one percent of Alzheimers disease cases, and usually takes effect before the age of 65. For some, it is as young as 30.
My dad started showing the symptoms of Alzheimers when he was just 41, and I was just 11. His dad, grandmother, and dads cousin had already died from the disease, and his younger sister soon got it too. There is now a young generation of our family waking up to the reality that well be next.
Ian Fleig & daughter Jess at the London DIAD Family Conference.
You often hear people talk about life-changing experiences but I dont think Ill ever enter a room again knowing that the next few words spoken will truly change everything.
Understanding Apoe And Risk Of Late
ApoE is most commonly linked with late-onset Alzheimers, a form of the disease which usually occurs in people over the age of 65 and accounts for the majority of Alzheimers cases. The gene comes in three common forms, or alleles: E2, E3 and E4. Everyone inherits an ApoE gene from each biological parent, and there are six possible ApoE combinations: E2/E2, E2/E3, E2/E4, E3/E3, E3/E4, E4/E4.
Analyzing data from past research of individuals who are cognitively healthy, Langbaum and colleagues found in a study that people who carry two copies of ApoE4 have a 30 to 55 percent risk of developing mild cognitive impairment or Alzheimers by the age of 85. The study also shows a 20 to 25 percent risk for people with one copy of the genetic variant. People with two copies of ApoE3 have an estimated risk of 10 to 15 percent. The researchers had less information available about people with ApoE2 as its rare, estimating that its associated risk with Alzheimers may be slightly lower or higher than 10 to 15 percent by the age of 85.
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To Know Or Not To Know
Unlike Tyrone, Gregory thinks everyone should learn their APOEe4 status. But also unlike Tyrone, she has not seen family members die of Alzheimerâs disease — though she learned since her test that she has a strong family history of the condition.
Gregory admits that she still worries about her brain health, and imagines she always will, every time she forgets something. But she has no regrets. âHad I not learned this, I never would have made any of these changes,â she says. âThis information has truly saved my life.â
Ultimately, the choice to take an APOEe4 test is a very personal one. But keep in mind, once you know your status, you canât reverse that knowledge. Whether or not the information saves your life, itâs likely to change it.
âThink hard about your decision,â Tyrone says. âGet your financial house in order first. Think about how the information might affect your family. Talk to a genetic counselor. And ask lots of questions. This is not to be taken lightly.â
Jamie Tyrone, author Fighting for My Live: How to Thrive in the Shadow of Alzheimerâs, San Diego.
Scott Weissman, MS, CGC, Chicago Genetics, Chicago.
Shirley Wu, PhD, director, Health Product Science, 23andMe, San Francisco.
New England Journal of Medicine: âEffect of Direct-to-Consumer Genomewide Profiling to Assess Disease Risk.â
Alzheimerâs Association: â2019 Alzheimerâs Disease Facts and Figures,â âGenetic Testing Statement.â
News Release, FDA.
Dementia Affects An Estimated 50 Million People Globally With Over 5 Million Of These Cases In The United States Alone
This number is expected to increase exponentially in the next several decades. Currently, there is no cure, but with the proper research and knowledge, you can learn how to handle the prognosis and progression of the disease.
Early detection is the key to making life more comfortable, and while not all cases are genetic or hereditary, DNA testing can help pinpoint markers for specific types of dementia.
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Pros And Cons Of Alzheimer’s Gene Test
“There is still a lot to explore in this,” Green says. “The bottom line is in conventional medical centers, ApoE is still an experimental test. We are not advocating using it clinically, and we will not use clinically at the present time.”
But that doesn’t mean people shouldn’t get the test — as long as they understand what they are doing, says Jeffery M. Vance, MD, PhD, director of the Center for Genomic Medicine at the University of Miami Institute for Human Genetics.
“It does not surprise me that with proper medical consultation, patients took the information in an appropriate fashion,” Vance tells WebMD. “As a doctor, you provide them the pros and cons — and that includes all the legal concerns, the medical concerns, and their concerns about the impact of the test on others in their family, their kids. Then let them make the decision.”
Perhaps the biggest argument against ApoE testing is that there’s no treatment to prevent or delay Alzheimer’s disease. That may soon change.
“In Alzheimer’s disease, we are talking about a disease where treatments are expected in the near future,” Green says. “Once there are treatments, the next clinical question is whether they delay Alzheimer’s onset in at-risk people. At that point, it will be important to know who is at higher risk.”
When Is Genetic Testing For Dementia Appropriate
In some cases, it may seem likely that a persons dementia is caused by a single-gene change for example, if the person has a very strong family history of dementia. In these cases, it may be appropriate to offer genetic testing to the person and to their family.
However in most families dementia will not be caused by a single-gene change. In these cases, genetic testing will not be appropriate. This is because testing for risk variants does not provide any certainty about the persons chances of developing dementia.
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How Will Genetic Testing Help You And Your Patient
In the case of genetic testing for early-onset familial AD, a positive test result for a known family gene mutation can result in:
- Relief from uncertainty
- An increased feeling of control
- Opportunity to plan life decisions
A negative test result for a known family gene mutation for early-onset familial AD can result in:
- Relief from fear of developing early-onset AD
- Knowledge that children are not at risk for early-onset AD
What Is The Purpose Of Pgd For Families Affected By Dementia
Not every attempt at PGD works. However, when it is successful, PGD allows people affected by a familial dementia to have a child who is almost certain not to have the genetic change that the affected parent has. This means that the child will not develop the type of dementia caused by that gene change.
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Mental Ability Tests To Diagnose Dementia
People with symptoms of dementia are given tests to check their mental abilities, such as memory or thinking.
These tests are known as cognitive assessments, and may be done initially by a GP.
There are several different tests. A common one used by GPs is the General Practitioner Assessment of Cognition .
Although these tests cannot diagnose dementia, they may show there are memory difficulties that need further investigation.
Most tests involve a series of pen-and-paper tests and questions, each of which carries a score.
These tests assess a number of different mental abilities, including:
- short- and long-term memory
- language and communication skills
- awareness of time and place
It’s important to remember that test scores may be influenced by a person’s level of education.
For example, someone who cannot read or write very well may have a lower score, but they may not have dementia.
Similarly, someone with a higher level of education may achieve a higher score, but still have dementia.
Alzheimer’s Gene Test: No Harm
Psychological Woes Rare When Gene Test ID’s Alzheimer’s Risk
Most doctors say no. They worry that you wouldn’t understand what it means to carry the ApoE-e4 gene. And they worry you’ll freak out and become clinically anxious or depressed.
Those doctors have been wrong on both counts, suggests a new study by Robert C. Green, MD, MPH, co-director of the Boston University Alzheimer’s disease program at Boston University, and colleagues.
“We have demonstrated that the assumption that it would be common to have psychological problems is not so,” Green tells WebMD. “And people do in fact understand the concept of a risk gene. They do not automatically move to the assumption that if they have the gene they will get Alzheimer’s.”
Understanding the results of an Alzheimer’s gene test is tricky. People who inherit a single copy of the gene are at increased risk of getting Alzheimer’s disease as they age. People who inherit two copies of the gene are at very high risk of the disease — even though it’s not a sure thing. And even if you don’t have the gene, you can still get Alzheimer’s disease.
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While It’s Commonly Thought To Be A Single Disease Dementia Is A Broad Term And Actually Encompasses A Range Of Diseases
Each presents with common symptoms that result in deteriorating mental, emotional and sometimes, physical capacity. It’s a progressive disease that worsens over time and without a cure, can prove to be fatal.
Early warning signs are usually detectable if you know what to look for. Some of these symptoms to be aware of include, but are not limited to:
- Memory loss
- Mood or personality changes
- Difficulty completing everyday tasks
Early detection is the key to implementing treatment, though there is no way to stop or cure most forms. While many who are diagnosed are past the age of 65, it’s not considered a normal part of aging.
However, early-onset dementia often affects those with the hereditary and genetic forms of the disease.
Some groups of people, such as those with Down syndrome, are more susceptible to developing dementia, with some studies suggesting approximately 75 percent of the population having Alzheimer’s.
This is likely due to their already impaired cognitive function and gene markers that come from the extra chromosome 21, particularly the one that involves the amyloid precursor protein, also known as APP.
Referral To A Specialist
If a GP is unsure about whether you have Alzheimer’s disease, they may refer you to a specialist, such as:
- a psychiatrist
- an elderly care physician
- a neurologist
The specialist may be based in a memory clinic alongside other professionals who are experts in diagnosing, caring for and advising people with dementia and their families.
There’s no simple and reliable test for diagnosing Alzheimer’s disease, but the staff at the memory clinic will listen to the concerns of both you and your family about your memory or thinking.
They’ll assess your memory and other areas of mental ability and, if necessary, arrange more tests to rule out other conditions.
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Genetic Testing For Alzheimers Disease
James M. Ellison, MD, MPH
Swank Center for Memory Care and Geriatric Consultation, ChristianaCare
- Expert Advice
Learn about the most common genes associated with the early- and late-onset forms of Alzheimers disease, and the current recommendations for genetic testing.
Can Alzheimers or other forms of dementia be passed along in the genes we inherit?
This is a very common question people ask, and the answer is not the same for all kinds of dementia. In this article we will focus on Alzheimers disease .
Genetic Testing Explained By An Expert
We asked Dr. G. Allen Power, MD, author of Dementia Beyond Drugs: Changing the Culture of Care and Dementia Beyond Disease: Enhancing Well-Being, for his insights on the Alzheimers genetic test.
First of all, the gene that carries the high risk of younger-onset Alzheimer’s across multiple family members is relatively rare, he explained. Only about 1-2% of people with Alzheimer’s have this type of disorder, and most other forms of dementia do not have a strong genetic component.
He added: Beyond that, some other genes may increase one’s lifetime risk, but not to such a great extent. The risk of getting Alzheimer’s, like most dementias, usually increases with age, meaning it’s mostly caused by a combination of factors that occur cumulatively as we live our lives, not by our genes. Even most of those who develop symptoms before age 65 are simply on the end of the bell curve and not subject to a strong genetic cause.
Like other experts, he strongly cautions those who get the Alzheimers genetic test.
I would recommend gene testing for those who have a very strong family history of younger-onset Alzheimer’s and who want to know if they carry the APOE4 gene, he said. But keep in mind that even having the gene is not a guarantee you will develop dementia.
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Yes There Is A Blood Test For Alzheimers Genes
While those who develop Alzheimers disease are likely to have similar symptoms, the two main types of Alzheimers are categorized as early-onset, or young-onset, Alzheimers and late-onset Alzheimers. Early-onset Alzheimers disease is less common, accounting for less than 10% of those with Alzheimers, and refers to individuals under 65 who develop Alzheimers. Late-onset refers to individuals 65 and older who develop the disease. Accordingly, researchers have found that there are specific genes or genetic mutations associated with each type of Alzheimers disease. Aside from the two main categorizations of Alzheimers, Familial Alzheimers disease is known with certainty to be linked to geneticshowever, it is quite rare, accounting for 1% or less of Alzheimers cases.
Genetic tests for Alzheimers disease are typically completed in the form of a blood test or saliva test. Below we detail common genes or genetic mutations that are tested for relating to late-onset and early-onset Alzheimers disease.
Genetic Testing And Counseling For Early Onset Familial Alzheimer Disease
“I am finding out this month. If I have it, I will never have kids. It’s got to stop somewhere in our family.” Tom Drury , 36.
“If I knew I carried the mutation, I would not be able to get up in the morning.” Jane Smith , 26, at risk for eFAD.
Interview with a Genetic Counselor: Jennifer Williamson is a genetic counselor at the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain and the Gertrude H. Sergievsky Center at Columbia University, New York
Genetic Status Protocol: Get a sense of the careful process you may want to ask for should you decide to find out about your genetic status.
Introduction Early onset familial Alzheimer disease is an autosomal-dominant genetic disease. This means that in each family it is caused by a mutation in a single gene, and that a single copy of the mutant gene, inherited from one parent, will cause the disease. The discovery in the mid 1990s of eFAD genes aroused the specter of knowing one’s genetic future, not only for patients but also for their children and entire families. Indeed, the age of genetic testing is here. DNA testing has been used since the mid-1990s for Huntington disease and certain types of cancer. The experience with these families provides helpful guidance for families with eFAD, who have turned to genetic testing more recently. Indeed, there is a large literature on genetic testing for HD and a small but growing literature for AD.
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If Youre Considering Utilizing A Dna Test You May Feel A Bit Overwhelmed By All The Options Available To Purchase Online Or To Have Administered Through Your Doctors Office
Heres the difference between a handful of common DNA tests that you may have seen commercials for or encountered online.
Ancestry DNA tests: This kind of DNA test is the kind you may have seen ads for, where it says submitting a DNA sample can help you find out more about your family history. Ancestry DNA tests are becoming more and more popular around the globe, and they often come with additional features such as family tree databases to help you compile your genealogy.
And, if you choose to participate, these DNA tests can also compare your DNA to that of people who have also submitted a test to identify potential relatives, which can work in the benefit of people who are adopted or dont know much of their family. Popular ancestry DNA tests include AncestryDNA, Family Tree DNA, and MyHeritage DNA, though more and more companies are offering this kind of DNA testing as time goes on.
At-Home Medical DNA tests: As more people want to know about their genetics, DNA testing companies have developed a variety of DNA test kits that can clue you on potential personal health risks. One of the biggest draws of these tests is that they can be taken within the privacy of your own home and theyre affordable which means that the information you gain from these tests can help you understand your personal health situation without the expense of a doctor-ordered DNA test.
If youre a woman, you wont have any Y-DNA for a DNA test kit to reveal .