Sunday, May 4, 2008
Monday, April 28, 2008
Heritability & Inbreeding
In a study performed on Swedish twins, researchers found the estimated heritability rate for Alzheimer's disease to be .74. They also found that the heritability rate for dementia to be .43, which is generally one of the beginning signs of Alzheimer's disease.
A heritability rate of .74 is very high, meaning that an individual has a very large chance of passing this disease on to their offspring.
Inbreeding would have a significant effect on Alzheimer's disease. Since it does have a high heritability rate, inbreeding would cause substantial changes within a population. This could cause the prevalence of Alzheimer's to become much higher than the current rate right now.
A heritability rate of .74 is very high, meaning that an individual has a very large chance of passing this disease on to their offspring.
Inbreeding would have a significant effect on Alzheimer's disease. Since it does have a high heritability rate, inbreeding would cause substantial changes within a population. This could cause the prevalence of Alzheimer's to become much higher than the current rate right now.
Friday, April 11, 2008
What I learned from the paper
After reading this paper, I realized how FFI and Alzheimer's are related diseases. Before reading this paper, I had never even heard of FFI. Both of these diseases are devistating diseases that effect many peoples lives across the world. By studying protein folding, we will hopefully, one day be able to understand what exactly causes these diseases to occur.
It is important for doctors to know and understand evolution. When they are making a diagnosis of an illness, they need to be able to understand how exactly the illness is affecting their patient at the current stage and also how the disease can evolve in the future.
It is important for doctors to know and understand evolution. When they are making a diagnosis of an illness, they need to be able to understand how exactly the illness is affecting their patient at the current stage and also how the disease can evolve in the future.
What I Learned From The Paper
Fatal Famalial Insomnia and Alzheimers Disease are fundamentally similar in many ways and the paper made me realize that. The protein misfolding of prions in FFI and the discussion paper made me realize how fundamentally tied they are. Although they produce effects, the general base for how these diseases happen is incredibly similar. Evolution is absolutely curcial in understanding the underlying principles through which these diseases develop. Considering the hereditary nature of these conditions, evolution is curcial in understanding them.
Ultimately, like Brad, I agree that doctors need a good grasp of evolution so they can see patterns within diseases and have a knowledge on how a certain disease or condition can develop. Through this doctors can more effectively develop treatments are incredibly importing in helping treat and hopefully cure these conditions and improve the overall health and wellbeing of many people. Through evolutionary science, doctors will hopefully one day be able to develop something to stop and potentially reverse the damage done by these conditions.
Ultimately, like Brad, I agree that doctors need a good grasp of evolution so they can see patterns within diseases and have a knowledge on how a certain disease or condition can develop. Through this doctors can more effectively develop treatments are incredibly importing in helping treat and hopefully cure these conditions and improve the overall health and wellbeing of many people. Through evolutionary science, doctors will hopefully one day be able to develop something to stop and potentially reverse the damage done by these conditions.
Jeremiah
Thursday, April 10, 2008
What I leanred from the paper
The paper on FFI helped me to see the similarities between AD and FFI. It showed that there are more diseases that are caused by protein mis-folding than just AD. The similarity between the two showed just how much of an impact protein folding has on the development of a person. After I answered the questions I learned that evolution does play a role in these diseases. When I first learned about both of these diseases I did not think evolution had much of a role, but now I understand that it has an impact on the development of these diseases and the heredity of them.
I think a doctor needs to know about evolution becuase a doctor needs to understand that it affects how diseases are going to develope and how they are going to be inherited from generation to generation. It is important that they understand what causes a disease and if evolution has a role in its cause because that could help them understand its heredity and how it may affect a person. They also should understand evolution becuase it is the basis for all of biology. If they do not understand or know about evolution then they do not have any basis for everything they have learned before. It is crutial that a doctor know about evolution to be effective at their job.
Brad
I think a doctor needs to know about evolution becuase a doctor needs to understand that it affects how diseases are going to develope and how they are going to be inherited from generation to generation. It is important that they understand what causes a disease and if evolution has a role in its cause because that could help them understand its heredity and how it may affect a person. They also should understand evolution becuase it is the basis for all of biology. If they do not understand or know about evolution then they do not have any basis for everything they have learned before. It is crutial that a doctor know about evolution to be effective at their job.
Brad
Wednesday, March 26, 2008
Questions on Case Study on FFI
1) Based on your research into Alzheimer’s disease and your interview, how are these two disorders alike?
Alzheimer’s disease (AD) is similar to Fatal Familial Insomnia (FFI) in many ways. For example, both of these debilitating disorders are the result of proteins in the body that have miss-folded. FFI is caused by prions that cause normal prion proteins in the brain to miss-fold just as AD is caused by the random miss-folding of proteins in the brain due to the build up of abnormal metabolites in the brain that trigger the miss-folding of the “amyloid beta” proteins. Another similarity is that the onset of these disorders in humans seems to take place in the later stages of life. A person usually begins to present with the symptoms of FFI between 40 and 60 years of age, with a possibility of symptoms beginning in a person as early as their 30’s. AD also presents in a person later in life as well, with symptoms appearing as early as their late 40’s. Approximately 63% of all people with AD are over the age of 65. These statistics show that both of these disorders present later in life, as opposed to presenting themselves in adolescence, or childhood. Both AD and FFI also are considered to be fatal diseases with no known cure. Because of the rarity of FFI there is little known research on finding a cure for the disease, while there is millions of dollars spent every year on AD research because of its higher prevalence in our society today. Because of this there are treatments for AD, while there are none for FFI. Both of these disorders are life altering and traumatic experiences for one to go through which is why more research is needed in the area of protein miss-folding.
2) What are prions?
The word prion is short for “proteinaceous infectious particle.” They are nonliving, self-replicating particles that are made up of proteins. They are believed to only infect the brain and are held responsible for neurodegenerative diseases such as Alzheimer’s disease (AD) and Fatal Familial Insomnia (FFI). They can arise from a mutation in a gene that code for a protein. They fold into unusual shapes and can cause other proteins to fold into unusual shapes as well which can lead to neurodegenerative diseases. They are believed to be both infectious and also hereditary. The gene that codes for prions can mutate and be passed on to the next generation in a family. However, despite being an infectious particle they do not provoke an immune response which makes it easier for them to cause problems in the brain.
3) FFI is an autosomal dominant disease, meaning that if an individual inherits just one dominant allele from either parent, they will develop the disease. However, this disease does not manifest itself phenotypically until after reproductive age. So can this disorder be acted on by natural selection? What about Alzheimer’s? What is maintaining these disorders in the population?
Yes, this disease can still be acted on by natural selection because it is still prevalent in the individual’s genome. The individual does not need to have the phenotype expressed in order for them to be able to pass on the affected gene. Natural selection acts on genotypes, not the phenotypes of a population. The disorder does not need to be expressed in order for it to be passed from one individual to another. Natural selection does not act on acquired characteristics that one acquires later in life. No, natural selection cannot act on Alzheimer’s disease its self because there is no specific gene that causes AD. Since there is no specific genotype for natural selection to act on then natural selection does not have any effect. FFI is being maintained in the population because it is an autosomal dominant disorder; this means that it only needs one affected gene for the disease to be present. Since it only needs one gene it is more likely that it will continue to be passed on from generation to generation. AD is still maintained in the population because it is caused by random miss-folding of proteins which genetics has no control over. Until we can find a way to inhibit this miss-folding Alzheimer’s will always be present in our population.
4) FFI is caused by a single mutation that, in the presence of methionine at amino acid position 129, changes aspartic acid to asparagine. This same mutation, in the presence of valine at position 129, causes a separate prion-disease called Creutzfeldt-Jacob syndrome. In cattle, the homologous syndrome is Mad Cow disease. How can studying protein folding and mis-folding help in understanding diseases like these?
If we were able to understand protein folding and miss-folding then we would be able to better understand the role of prions in this process. If we were able to understand prions better then maybe we would be able to understand what is causing these mutations in our genome. Having a better understanding of protein folding and miss-folding would essentially allow us to work backwards to eventually learn what is causing these mutations that are ultimately leading to these debilitating diseases. From understanding protein folding better we would possibly be able to reverse its effects on the brain and possibly find a cure to AD and FFI.
5) This disease was discussed last week on Medical Mysteries:
(http://video.google.com/videoplay?docid=760959254431325673&q=fatal+familial+insomnia&total=3&start=0&num=10&so=0&type=search&plindex=0
The two sisters in this story lost their mother to FFI. One sister chose to be tested for the mutation, while the other sister did not. Would each of you want to know whether or not you had a disease such as this, or would you rather remain unaware?
Brad- I would want to be tested for the disease because I feel that I would then have a limited amount of time left. Because of this I would want to know so that I could assure that I would live the way that I want to live in the short amount of time that I may have.
Chelse- I would not want to be tested for a disease like this. Because I don’t want to live my life knowing that it could end soon. If I were to know then I would feel that I have pressure to accomplish what I want to accomplish in life. I would feel that I have a short amount of time to live my life the way that I want.
Alzheimer’s disease (AD) is similar to Fatal Familial Insomnia (FFI) in many ways. For example, both of these debilitating disorders are the result of proteins in the body that have miss-folded. FFI is caused by prions that cause normal prion proteins in the brain to miss-fold just as AD is caused by the random miss-folding of proteins in the brain due to the build up of abnormal metabolites in the brain that trigger the miss-folding of the “amyloid beta” proteins. Another similarity is that the onset of these disorders in humans seems to take place in the later stages of life. A person usually begins to present with the symptoms of FFI between 40 and 60 years of age, with a possibility of symptoms beginning in a person as early as their 30’s. AD also presents in a person later in life as well, with symptoms appearing as early as their late 40’s. Approximately 63% of all people with AD are over the age of 65. These statistics show that both of these disorders present later in life, as opposed to presenting themselves in adolescence, or childhood. Both AD and FFI also are considered to be fatal diseases with no known cure. Because of the rarity of FFI there is little known research on finding a cure for the disease, while there is millions of dollars spent every year on AD research because of its higher prevalence in our society today. Because of this there are treatments for AD, while there are none for FFI. Both of these disorders are life altering and traumatic experiences for one to go through which is why more research is needed in the area of protein miss-folding.
2) What are prions?
The word prion is short for “proteinaceous infectious particle.” They are nonliving, self-replicating particles that are made up of proteins. They are believed to only infect the brain and are held responsible for neurodegenerative diseases such as Alzheimer’s disease (AD) and Fatal Familial Insomnia (FFI). They can arise from a mutation in a gene that code for a protein. They fold into unusual shapes and can cause other proteins to fold into unusual shapes as well which can lead to neurodegenerative diseases. They are believed to be both infectious and also hereditary. The gene that codes for prions can mutate and be passed on to the next generation in a family. However, despite being an infectious particle they do not provoke an immune response which makes it easier for them to cause problems in the brain.
3) FFI is an autosomal dominant disease, meaning that if an individual inherits just one dominant allele from either parent, they will develop the disease. However, this disease does not manifest itself phenotypically until after reproductive age. So can this disorder be acted on by natural selection? What about Alzheimer’s? What is maintaining these disorders in the population?
Yes, this disease can still be acted on by natural selection because it is still prevalent in the individual’s genome. The individual does not need to have the phenotype expressed in order for them to be able to pass on the affected gene. Natural selection acts on genotypes, not the phenotypes of a population. The disorder does not need to be expressed in order for it to be passed from one individual to another. Natural selection does not act on acquired characteristics that one acquires later in life. No, natural selection cannot act on Alzheimer’s disease its self because there is no specific gene that causes AD. Since there is no specific genotype for natural selection to act on then natural selection does not have any effect. FFI is being maintained in the population because it is an autosomal dominant disorder; this means that it only needs one affected gene for the disease to be present. Since it only needs one gene it is more likely that it will continue to be passed on from generation to generation. AD is still maintained in the population because it is caused by random miss-folding of proteins which genetics has no control over. Until we can find a way to inhibit this miss-folding Alzheimer’s will always be present in our population.
4) FFI is caused by a single mutation that, in the presence of methionine at amino acid position 129, changes aspartic acid to asparagine. This same mutation, in the presence of valine at position 129, causes a separate prion-disease called Creutzfeldt-Jacob syndrome. In cattle, the homologous syndrome is Mad Cow disease. How can studying protein folding and mis-folding help in understanding diseases like these?
If we were able to understand protein folding and miss-folding then we would be able to better understand the role of prions in this process. If we were able to understand prions better then maybe we would be able to understand what is causing these mutations in our genome. Having a better understanding of protein folding and miss-folding would essentially allow us to work backwards to eventually learn what is causing these mutations that are ultimately leading to these debilitating diseases. From understanding protein folding better we would possibly be able to reverse its effects on the brain and possibly find a cure to AD and FFI.
5) This disease was discussed last week on Medical Mysteries:
(http://video.google.com/videoplay?docid=760959254431325673&q=fatal+familial+insomnia&total=3&start=0&num=10&so=0&type=search&plindex=0
The two sisters in this story lost their mother to FFI. One sister chose to be tested for the mutation, while the other sister did not. Would each of you want to know whether or not you had a disease such as this, or would you rather remain unaware?
Brad- I would want to be tested for the disease because I feel that I would then have a limited amount of time left. Because of this I would want to know so that I could assure that I would live the way that I want to live in the short amount of time that I may have.
Chelse- I would not want to be tested for a disease like this. Because I don’t want to live my life knowing that it could end soon. If I were to know then I would feel that I have pressure to accomplish what I want to accomplish in life. I would feel that I have a short amount of time to live my life the way that I want.
Monday, March 17, 2008
Interview with Dr. Burns about Alzheimers
1) Why did you choose to do work with Alzheimers?
I ended up studying AD largely for academic reasons and out of interest more than any personal story. I was originally drawn into neurology out of an interest in the brain: all the mysteries of the brain and the fact that it is what makes us human. As a neurologist, you quickly learn that everything the brain can do, it can also do wrong and so many of the things that we take for granted about ourselves such as our personality, ability to talk, use tools, etc are affected by various brain disease. Within neurology, these types of problems fall into the realm of behavioral neurology and within behavioral neurology falls AD, the most common cause of behavioral neurology problems. The huge problem of AD and the fact that we are only on the verge of developing effective treatment options was appealing to me as well.
2) Do you have any accounts of patients with Alzheimers? If so, can you share a story?
Too numerous to give just one. I see patients with AD on a nearly daily basis.
3) Why should a doctor/researcher treating/studying Alzheimers know about evolution?
I’m not sure evolution plays a direct role in treating or studying Alzheimer’s but it is one of the foundations of biology and certainly plays an indirect role in the foundation for anyone studying biological sciences and medicine.
4) Why would it help for these people to know about protein folding?
One of the leading hypotheses about the cause of AD is that it is a problem with protein folding. The amyloid protein is normally found in everyone but it may be that a problem with the processing of this protein leads to protein folding abnormalities that result in a toxic form. The accumulation of the toxic form of amyloid may lead to the death of neurons and result ultimately in the disorder. We are not yet certain that the amyloid accumulations, however, are the cause of the disease as opposed to the byproduct of the disease process.
5) How important is it to find a cure for Alzheimers?
AD affects 5 million Americans and accounts for an estimated 100 billion dollars annually in costs. It is age-related and is a common as 40 – 50% in individuals over the age of 85. Combine that fact with the fact that the fastest growing segment of the population is over age 85 and you can see we have a serious problem from societal, economic, and personal (we’re all at high risk) levels. A cure would have enormous implications. Short of that, delaying the onset of the disease across the population by 5 years would also have an enormous effect by cutting the prevalence by 50%.
6) How important of a role do you think grid computing plays in the search for a cure?
It’s likely to have an impact though I don’t think the impact it will have is yet clear. As an example of how more powerful computing can have an impact on AD research, we use parallel computing on a supercomputer at UCLA to examine our brain images and the power and efficiency of this type of computing has a big impact on what we can do.
7) What misconceptions exist about Alzheimers?
One big one is that it is untreatable. There are treatments that are effective and AD should be considered a treatable disorder. The effects of treatment are not good enough. They stabilize people for about a year but people continue to progress and eventually will die of the disease so we need better treatments. Nevertheless, proven therapies exist.
8) Would having a better understanding of protein folding and how it causes Alzheimers help in finding a cure?
If protein folding is at the root of the disease, understanding the hows and whys of the protein folding abnormalities would give us therapeutic targets. For instance, if we knew where the key folding problem occurred and what was driving the change, we could develop drugs that block that abnormal process and potentially stop the disease process.
9) What is some of the latest research on Alzheimers if you know of any?
There is a lot of ongoing research in AD. We are doing a lot at KU (some of it outlined at KUAlzheiemer.org. You could also try clinicaltrials.gov
I ended up studying AD largely for academic reasons and out of interest more than any personal story. I was originally drawn into neurology out of an interest in the brain: all the mysteries of the brain and the fact that it is what makes us human. As a neurologist, you quickly learn that everything the brain can do, it can also do wrong and so many of the things that we take for granted about ourselves such as our personality, ability to talk, use tools, etc are affected by various brain disease. Within neurology, these types of problems fall into the realm of behavioral neurology and within behavioral neurology falls AD, the most common cause of behavioral neurology problems. The huge problem of AD and the fact that we are only on the verge of developing effective treatment options was appealing to me as well.
2) Do you have any accounts of patients with Alzheimers? If so, can you share a story?
Too numerous to give just one. I see patients with AD on a nearly daily basis.
3) Why should a doctor/researcher treating/studying Alzheimers know about evolution?
I’m not sure evolution plays a direct role in treating or studying Alzheimer’s but it is one of the foundations of biology and certainly plays an indirect role in the foundation for anyone studying biological sciences and medicine.
4) Why would it help for these people to know about protein folding?
One of the leading hypotheses about the cause of AD is that it is a problem with protein folding. The amyloid protein is normally found in everyone but it may be that a problem with the processing of this protein leads to protein folding abnormalities that result in a toxic form. The accumulation of the toxic form of amyloid may lead to the death of neurons and result ultimately in the disorder. We are not yet certain that the amyloid accumulations, however, are the cause of the disease as opposed to the byproduct of the disease process.
5) How important is it to find a cure for Alzheimers?
AD affects 5 million Americans and accounts for an estimated 100 billion dollars annually in costs. It is age-related and is a common as 40 – 50% in individuals over the age of 85. Combine that fact with the fact that the fastest growing segment of the population is over age 85 and you can see we have a serious problem from societal, economic, and personal (we’re all at high risk) levels. A cure would have enormous implications. Short of that, delaying the onset of the disease across the population by 5 years would also have an enormous effect by cutting the prevalence by 50%.
6) How important of a role do you think grid computing plays in the search for a cure?
It’s likely to have an impact though I don’t think the impact it will have is yet clear. As an example of how more powerful computing can have an impact on AD research, we use parallel computing on a supercomputer at UCLA to examine our brain images and the power and efficiency of this type of computing has a big impact on what we can do.
7) What misconceptions exist about Alzheimers?
One big one is that it is untreatable. There are treatments that are effective and AD should be considered a treatable disorder. The effects of treatment are not good enough. They stabilize people for about a year but people continue to progress and eventually will die of the disease so we need better treatments. Nevertheless, proven therapies exist.
8) Would having a better understanding of protein folding and how it causes Alzheimers help in finding a cure?
If protein folding is at the root of the disease, understanding the hows and whys of the protein folding abnormalities would give us therapeutic targets. For instance, if we knew where the key folding problem occurred and what was driving the change, we could develop drugs that block that abnormal process and potentially stop the disease process.
9) What is some of the latest research on Alzheimers if you know of any?
There is a lot of ongoing research in AD. We are doing a lot at KU (some of it outlined at KUAlzheiemer.org. You could also try clinicaltrials.gov
Subscribe to:
Posts (Atom)
