Expression In Various Cell Types
The expression of genes was assigned to specific cell classes of the adult brain, as described previously. Briefly, middle temporal gyrus single-nucleus transcriptomes from the Allen Brain Atlas dataset were used to annotate and select six main cell classes using Seurat 3.1.1 : glutamatergic neurons, GABAergic neurons, astrocytes, oligodendrocytes, microglia and endothelial cells. Enrichment analyses were performed by using the mean gene expression per nucleus for each cell type relative to the total expression summed across cell types as a quantitative covariate in a MAGMA gene property analysis.
Cause #: Mild Cognitive Impairment
People who already have mild cognitive impairment may be at an increased risk of developing full-blown Alzheimers. A mild cognitive impairment doesnt necessarily impact a persons daily life in a major way. However, it can have some effects on memory, thinking skills, visual perception, and the ability to make sound decisions.
Scientists are trying to understand why some cases of mild cognitive impairment progress into Alzheimers. A
Do Genes Cause Diseases
Genetic mutations can cause diseases. If a person inherits a genetic mutation that causes a certain disease, then he or she will usually get the disease. Sickle cell anemia, cystic fibrosis, and some cases of early-onset Alzheimer’s disease are examples of inherited genetic disorders.
Other changes or differences in genes, called genetic variants, may increase or decrease a person’s risk of developing a particular disease. When a genetic variant increases disease risk but does not directly cause a disease, it is called a genetic risk factor.
Identifying genetic variants may help researchers find the most effective ways to treat or prevent diseases such as Alzheimer’s in an individual. This approach, called precision medicine, takes into account individual variability in genes, environment, and lifestyle for each person.
The expression of geneswhen they are switched on or offcan be affected, positively and negatively, by environmental and lifestyle factors, such as exercise, diet, chemicals, or smoking. The field of epigenetics is studying how such factors can alter a cell’s DNA in ways that affect gene activity.
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Reducing Your Risk Of Developing Dementia
As mentioned earlier, genes increase the risk of dementia but do not cause it in most cases. There are multiple risk factors associated with dementia, including cardiovascular diseases, diabetes, and smoking, that can be managed to help in preventing dementia. Maintaining a healthy lifestyle with physical exercise, a balanced Mediterranean diet, low levels of alcohol intake and abstinence from smoking can help in reducing the risk of dementia.
Individuals with substance use disorders are often at an increased risk of developing dementia. In addition, family members of an individual with dementia may turn to substances to deal with the stress of caring for their loved one. If you or a loved one suffers from a substance use disorder, The Recovery Village can help. Contact us today to learn about specialized treatment programs that can work well for your situation.
Medical Disclaimer: The Recovery Village aims to improve the quality of life for people struggling with a substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare provider.
Other Rare Types Of Dementia
Other rare types of dementia that can be passed down through the family include Huntingtons disease and Familial Prion disease. These diseases have a 50/50 chance of being passed on because they are caused by a single faulty dominant gene.
This means that, if you inherit a healthy gene from one parent and a faulty gene from the other parent, the faulty one will always be the one that is used because its the dominant gene.
For more information, care and support services, please refer to the Huntingtons Disease Association or the National Prion Clinic at UCL.
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How Can Genes Cause Dementia
Most often, dementia is caused by a complex disease in which genes are only one factor. When this happens, the dementia develops as a result of many different factors. In these cases, genes do not directly cause it to develop.
It is not possible to directly inherit dementia when it is caused by a complex disease.
Alzheimer’s Disease Inherited Through Maternal Line Study Finds
- Date:
- Elsevier
- Summary:
- A family history of Alzheimer’s disease significantly increases the risk for developing this disorder, but a new study suggests that which of your parents has the disease is very important.
A family history of Alzheimer’s disease significantly increases the risk for developing this disorder, but a new study in Biological Psychiatry suggests that which of your parents has the disease is very important.
Alzheimer’s is the most common form of dementia in late-life, affecting over 5 million elderly in the United States alone. In order to develop preventative treatments, it is necessary to identify those individuals who are at highest risk for developing Alzheimer’s.
Although individuals with a parental history of Alzheimer’s are at increased risk for developing the disease, the specific biological and genetic mechanisms accounting for this increased risk are not known.
An important consideration may be a phenomenon called genomic imprinting, where the pattern of the inherited disease differs based on whether the risk genes are inherited from the mother or the father. Imprinting is a type of epigenetic regulation, meaning that long lasting changes in gene function are produced through regulatory mechanisms rather than by altering the sequence of the DNA.
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Can Alzheimer’s Disease Be Prevented
Unfortunately, there isn’t much to be done to avoid certain risk factors such as gender and age that increase the risk of developing Alzheimer’s disease.
Research does show that specific lifestyle changes could help. Maintaining a healthy diet, exercising regularly, and cutting down on smoking and drinking alcohol could reduce your risk of developing the disease.
In cases where the disease has already developed, these lifestyle changes could also potentially help slow the disease’s progression.
Which Genes Are Responsible For Alzheimers
APOE-e4 is the most common gene associated with Alzheimers, but it is only a risk gene. It doesnt necessarily guarantee youll develop the disease.
Alzheimers disease genetics can seem complicated. That might be because researchers dont know every gene on every chromosome that may lead to Alzheimers. But scientists have figured out 3 deterministic genes that result in Alzheimers disease, as well as several genes and genetic mutations that bring a greater risk of Alzheimers.
Deterministic genes are only found in an estimated 1% of Alzheimers cases. Here are the 3 deterministic genes that directly cause Alzheimers, particularly early-onset Alzheimers disease:
Mutations or variations of the following genes may put you at higher risk of Alzheimers, especially late-onset Alzheimers disease:
- ABCA7
- TREM2
- SORL1
Apolipoprotein E-e4 was identified in 1993 as the first gene variation found to increase the risk of Alzheimers disease. According to the Alzheimers Association, researchers estimate that between 40-65% of people diagnosed with Alzheimers have the APOE-e4 gene.
There is a blood test that tests for APOE-e4. This genetic test helps inform an Alzheimers diagnosis, though it cannot diagnose Alzheimers by itself.
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Medical Research On Is Dementia Hereditary
Researchers believe that dementia is caused by diseases that are a result of the lifestyle they lead. Rather than developing dementia from the DNA that they have inherited from their parents.
Some conditions that can lead to diseases of the brain in later life can be inherited. Diseases such as Huntingtons are inherited diseases and other forms of dementia such as frontotemporal dementias have a greater risk of being inherited from parent to child by as much as 50%.
In generalmost dementias such as Alzheimers disease and Vascular dementiaare not inherited diseases and are a consequence of the lifestyles we choose to lead. Much more evidence is still needed to confirm this research.
What Role Do Our Genes Play In Dementia
As dementia is so common, many of us will have a relative living with the condition but this does not mean we will develop it too.
Dementia is caused by diseases that affect the brain, such as Alzheimers disease. The likelihood of developing dementia will usually depend on a complex mix of factors like our age, medical history and lifestyle, as well as our genes. Most cases of dementia are not directly caused by genes we inherit from our parents.
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Genes Associated With Genetic Ftd
C9ORF72 gene
- C9 mutations cause FTD, amyotrophic lateral sclerosis or a combination of both conditions in a person.
- Whether a person will develop FTD or ALS or a combination cannot be predicted for healthy people at risk.
- C9 mutations are the most common cause of genetic FTD. They are also the most common cause of genetic ALS.
MAPT gene .
- MAPT mutations usually cause FTD .
- Sometimes MAPT mutations cause conditions associated with progressive supranuclear palsy or corticobasal degeneration pathology. People with these pathologies often have a type of movement disorder.
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.
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How Is Alzheimer’s Disease Treated
There is currently no cure for Alzheimer’s disease. However, scientists have developed treatments that can reduce the severity of some of the condition’s debilitating symptoms.
Treating Alzheimer’s disease effectively typically involves a combination of medication and therapy. Specific lifestyle changes are also recommended to help a person with the condition live a more fully functioning life.
The Genetics Of Alzheimer’s Disease
In order to understand the genetics of Alzheimer’s disease , it is first necessary to understand the basics of genetics. Most cells of the body have 46 chromosomes, grouped into 23 pairs. One member of each chromosome pair is inherited from each parent. Each chromosome is composed of deoxyribonucleic acid , the genetic material that provides instructions for how the body grows and functions . Genes are segments of DNA found on each of our chromosomes. Each gene provides the instructions for a specific protein with a specific function. Certain variations within the genes may lead to differences in individual traits . Other variations in gene sequence may be disease-causing. When a gene variant causes disease, it is often referred to as a mutation.
Many studies have been carried out to identify gene variants associated with an increased risk for developing AD. Two different types of variants have been identified: disease-causing mutations in individuals with early-onset familial AD and susceptibility variants in individuals with late-onset AD. Those with early-onset familial AD are likely to develop AD before the age of 65 and are likely to have family members who also have early-onset AD. These individuals account for less than 5% of all AD cases. Those with late-onset AD account for the vast majority of AD cases. Those with late-onset AD may or may not have similarly affected family members.
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Abnormal Buildup In The Brain
The buildup of two abnormal structures in the brain, called amyloid plaques and neurofibrillary tangles, is common in AD. The buildup may be part of the cause, although scientists are unclear about if these findings could be the result of the disease instead.
Amyloid plaques are clumps of beta-amyloid, a piece of a protein that is found in the normal brain. When these beta-amyloid proteins clump together, they form plaques that can disrupt communication between nerve cells and cause brain inflammation. People with AD have an abundance of these plaques in the hippocampus, the part of the brain involved in memory. The transfer of short-term memories into long-term memories is often disrupted in AD. Learn about other symptoms of Alzheimers disease.
Neurofibrillary tangles are fibrous tangles of an abnormal protein called tau. Tau is an important fiber-like protein that keeps microtubules in the brain stable. Microtubules move nutrients, molecules, and information to other cells. When tau is harmfully altered, possibly due to genetic mutation, the fibers get twisted up together. This makes the microtubules unstable and causes them to disintegrate. This effect can collapse the whole neuron transport system.
Will I Inherit Dementia From My Parents Is It Hereditary
If youre caring for a relative living with dementia, its natural to be concerned about whether or not you or your children will develop the disease. In reality, there are actually different kinds of dementia and most of them are not hereditary.
Read on to learn about the common types of dementia, and what the chances are for people with relatives diagnosed with dementia to develop the disease.
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Is Alzheimer’s Disease Genetic
Researchers have observed that a genetic mutation is responsible for many cases of Alzheimer’s disease. However, they’ve been unable to identify which specific gene is responsible for the condition.
Alzheimer’s disease can be classified into early-onset Alzheimer’s and late-onset Alzheimer’s. Less than 10% of people with Alzheimer’s have early-onset Alzheimer’s. A percentage of this number is thought to be caused by inherited genes. This means a close relative passed down a mutated gene that led to the development of the condition.
“Alzheimer’s disease typically starts in older people aged 60 and above. It is associated with a gene called Apolipoprotein E4 . Possessing APOE4 can increase the risk of developing Alzheimer’s. Studies have found having two copies of APOE4 can increase risk by ten-fold, says Nikhil Palekar, MD, Medical Director of the Stony Brook Center of Excellence for Alzheimer’s Disease.
Dr. Palekar also notes that a person’s risk of being diagnosed with Alzheimer’s disease increases three-fold if they have one copy of APOE4. “This is a similar risk if you have a first-degree relative with Alzheimer’s disease,” says Dr. Palekar.
Family History Of Dementia
Individuals with a family history of dementia may be at a higher risk of developing dementia. However, this may be due to the inheritance of gene variants that increase susceptibility to dementia rather than cause it directly. In such cases, chances of getting dementia are also influenced by social and environmental factors as well as lifestyle choices.
In the case of familial dementia, genetic testing may be useful. Such genetic testing is available for genes involved in Alzheimers disease and frontotemporal dementia . This can help people to be vigilant about the signs and symptoms of dementia and increase awareness about available tests and treatments. Although there are no cures available for dementia, individuals may participate in ongoing clinical trials.
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Can Alzheimers Disease Be Inherited
In the vast majority of cases , Alzheimers disease is not inherited.
The most important risk factor for Alzheimer’s disease is age. Because Alzheimer’s disease is so common in people in their late 70s and 80s, having a parent or grandparent with Alzheimer’s disease at this age does not change your risk compared to the rest of the population.
However, if somebody has developed Alzheimers disease at an earlier age there is a greater chance that it may be a type of Alzheimers disease that can be passed on.
Areas Of Future Research
According to the National Institute on Aging, here are some questions to answer in future research into the association between Alzheimers and genetics:
- How genetics interact with lifestyle factors to affect Alzheimers risk
- How the disease process begins
- Why Alzheimers is the most common cause of dementia symptoms
- What the difference in Alzheimers between various racial groups and sexes
- How to prevent Alzheimers
- What treatments are possible and effective
- Who is most at risk for Alzheimers, and why
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Cause #: Past Head Trauma
The Alzheimers Association states that scientists have found a link between traumatic brain injury and a greater risk of dementia. After a traumatic injury, your brain creates large amounts of beta amyloid. This is the same protein that develops into the damaging plaques that are a hallmark of Alzheimers.
Theres one difference: After a traumatic brain injury, beta amyloid, although present, doesnt clump into plaques. However, the damage may increase the risk of them doing so later in life.