rilesa:
credit-3990
total-18
Top user:
credit-668237867
total-3450250
Monday, May 5, 2008
Sunday, April 27, 2008
Heritability of Alzheimer's
1. Provide an estimate of h squared for the disorder. Based on this, discuss how much influence selection could have on this trait.
In a study, Heritability for Alzheimer's disease: the study of dementia in Swedish twins done in March of 1997, they wanted to find all cases of dementia in an established twin registry and to see what the heritability was for Alzheimer's. The study included sixty-five pairs of twins, both monozygotic and dizygotic twins, that either one or both of the twins had dementia. The concordance rate for monozygotic twins was 67 percent where as the dizygotic rate was 22 percent. According to this article, the estimated heritability for Alzheimer's is .74. The differences of when the onset of Alzheimer's came in the twins may be because of environmental factors. There is more known about the genetic effects of early onset Alzheimer's then known about late onset Alzheimer's. The influence of selection on Alzheimer's would not have a big impact because onset of Alzheimer's is after reproductive age. If there is a history of Alzheimer's in the family, a couple may choose not to have kids or adopt so that they would not be passing on the trait.
http://www.ncbi.nlm.nih.gov/pubmed/9060980- Heritability for Alzheimer's disease: the study of dementia in Swedish twins
2. What effect might inbreeding have on this disorder?
Since Alzheimer's has a heritability of .74, the effect of inbreeding may be substantial. The more inbred a population is, the higher the heritability could potentially be. The heterozygosity would go down, so there would be little variation in alleles.
In a study, Heritability for Alzheimer's disease: the study of dementia in Swedish twins done in March of 1997, they wanted to find all cases of dementia in an established twin registry and to see what the heritability was for Alzheimer's. The study included sixty-five pairs of twins, both monozygotic and dizygotic twins, that either one or both of the twins had dementia. The concordance rate for monozygotic twins was 67 percent where as the dizygotic rate was 22 percent. According to this article, the estimated heritability for Alzheimer's is .74. The differences of when the onset of Alzheimer's came in the twins may be because of environmental factors. There is more known about the genetic effects of early onset Alzheimer's then known about late onset Alzheimer's. The influence of selection on Alzheimer's would not have a big impact because onset of Alzheimer's is after reproductive age. If there is a history of Alzheimer's in the family, a couple may choose not to have kids or adopt so that they would not be passing on the trait.
http://www.ncbi.nlm.nih.gov/pubmed/9060980- Heritability for Alzheimer's disease: the study of dementia in Swedish twins
2. What effect might inbreeding have on this disorder?
Since Alzheimer's has a heritability of .74, the effect of inbreeding may be substantial. The more inbred a population is, the higher the heritability could potentially be. The heterozygosity would go down, so there would be little variation in alleles.
Friday, April 11, 2008
Ashley Riles
Alzheimer's is a fascinating disease that is similar to many other diseases, which I learned that by studying similar diseases it may help find out how a certain one may progress. If Alzheimer's is linked to certain genes and another disease is also linked to some of those same genes then finding information about one could help the other whether the genes are inhertable or a mutation. If we find out what causes amyloid plaques in FFI, then we may figure out why they are in patients that have Alzheimer's. If doctors know about population genetics then they can provide patients the prevalence of the genetic diseases. It is helpful that docters know about evolution since diseases have changed and are continuing to change because of mutations, genetic drift, and natural selection. By studying how diseases and other pathogens have evolved in the past, helps to understand modes of reproduction, population structure, genetic variance, antibiotic resistence and virulence that may affect human body.
Thursday, April 10, 2008
Grant Hengst
What I learned about our topic is that Alzheimers is a disease doctors are still working on to find more things about it. There is a huge search for the cure and since people are living longer now there is a higher percentage of elderly people getting Alzheimers. Also, I didn't know that there were high cholesterol drugs that were being looked at as a possible side effect of solving Alzheimers. I think a doctor should know about evolution because the knowledge of evolution furthers the understanding of the human body. If doctors would take an evolution course they could understand the concepts of mutation and genetic drift, which would help them greatly with understanding how some diseases start out as, for example Influenza (flu). Also, like Dr. Felzien said studying animal models and finding which animal was the best compared to humans would be a good evolution analysis to help doctors in curing diseases.
Monday, March 17, 2008
Case Study on FFI
1. How are Alzheimer's disease and Fatal Familial Insomnia (FFI) similar?
They are both degenerative of the brain and both contain the amyloid plaques. They are also found mainly in people that are aging with the four stages including phobias and hallucinations.
2. What are prions?
Prions are protein segments that could cause infection that may lead to some forms of dementia. Currently all prion diseases are untreatable and thought to be fatal. In some fungi, proteins showing prion-type behavior are also found and this had been quite important in helping to understand prions in mammals. However, fungal prions do not appear to cause disease in their hosts and may even give an evoluntionary advantage through a form of protein-based inderitance.
3. So can this disorder be acted on by natural selection? What about Alzheimer's? What is maintaining these disorders in the population?
FFI and Alzheimer's cannot be acted on by natural selection because the affects are after child bearing years in which potentially affected individuals may have already had children that may also be potentially affected. To maintain these disorders in the population, different techniques can be used to detect the defective gene in FFI yet in Alzheimer's scientist are not sure if its heritable.
4. How can studying protein folding and mis-folding help in understanding disease like these?
First off studying cattle would be good because it would give us a good source for studying evolutionary analysis compared with humans because they are homologous. By looking at Mad Cow disease and other degenerative syndromes in humans we can understand why accumulation of abnormal cleavage and glutamine develops. We can also understand mis-folding by knowing why plaques and tangles occur.
5. Would each of you want to know whether or not you had a disease such as this, or would you rather remain unaware?
We would definitely want to know so we could live life to the fullest and spend quality time with our family and friends. Also, we would know not to pass it on to our offspring, therefore we would not be affecting our children so they don't have to go through the same disorder.
They are both degenerative of the brain and both contain the amyloid plaques. They are also found mainly in people that are aging with the four stages including phobias and hallucinations.
2. What are prions?
Prions are protein segments that could cause infection that may lead to some forms of dementia. Currently all prion diseases are untreatable and thought to be fatal. In some fungi, proteins showing prion-type behavior are also found and this had been quite important in helping to understand prions in mammals. However, fungal prions do not appear to cause disease in their hosts and may even give an evoluntionary advantage through a form of protein-based inderitance.
3. So can this disorder be acted on by natural selection? What about Alzheimer's? What is maintaining these disorders in the population?
FFI and Alzheimer's cannot be acted on by natural selection because the affects are after child bearing years in which potentially affected individuals may have already had children that may also be potentially affected. To maintain these disorders in the population, different techniques can be used to detect the defective gene in FFI yet in Alzheimer's scientist are not sure if its heritable.
4. How can studying protein folding and mis-folding help in understanding disease like these?
First off studying cattle would be good because it would give us a good source for studying evolutionary analysis compared with humans because they are homologous. By looking at Mad Cow disease and other degenerative syndromes in humans we can understand why accumulation of abnormal cleavage and glutamine develops. We can also understand mis-folding by knowing why plaques and tangles occur.
5. Would each of you want to know whether or not you had a disease such as this, or would you rather remain unaware?
We would definitely want to know so we could live life to the fullest and spend quality time with our family and friends. Also, we would know not to pass it on to our offspring, therefore we would not be affecting our children so they don't have to go through the same disorder.
Thursday, February 14, 2008
Interview of Folding of Proteins-Alzheimers
Dr. Felzien, Rockhurst University
Why did you choose this field?
I started out wanting to be a social worker but after I took a biology class I thought genetics was interesting. Also, I liked the molecular aspects like proteins and knowing how cells work.
Why should a doctor or researcher studying Alzheimer's know about evolution?
By researching animal models you can study the disease and studying the difference between human and animal genetics. By studying which animal model would be the best compared to humans would be a good source for evolutionary analysis.
Why should they know about protein mis-folding?
Knowing how proteins mis-fold we can understand diseases and know how the accumulation of abnormal cleavage and glutamine develops in Alzheimer's. Also, knowing why plaques and tangles occur can help understand why and if they are actually mis-folding.
How important is the search for a cure or finding out why/how Alzheimer's happens?
This is a huge search for a cure. One has to find the answers to where are the mutations/dispositions? People are living longer so now there is a higher percentage of elderly people getting Alzheimer's. The percentages alone show that 0.1% get Alzheimer's at age 60 while at age 80 it's 10%. Also, at age 90 it is over 30%, which shows that aging may be a reason why Alzheimer's is on the rise.
What do you think about using grid computing in this search?
If it's looking at different database of proteins it can look at little differences in the folding of proteins and differences from person to person.
Are there any new means of prevention of Alzheimer's?
There are many drugs now that delay the onset of deterioration. Also, there is treatments that block the plaques, but there are certain drugs that can't cross the membrane. Oxidation reactions is looking to be treated with forms of antioxidants.
Any other interesting stories dealing with folding of proteins or Alzheimer's?
High cholesterol drugs that lower cholesterol are being looked at as a possible side effect of slowing Alzheimer's. Prions (proteins in the body) can get mis-folded and the one that is mis-folded may have the mutation that will effect the brain.
Why did you choose this field?
I started out wanting to be a social worker but after I took a biology class I thought genetics was interesting. Also, I liked the molecular aspects like proteins and knowing how cells work.
Why should a doctor or researcher studying Alzheimer's know about evolution?
By researching animal models you can study the disease and studying the difference between human and animal genetics. By studying which animal model would be the best compared to humans would be a good source for evolutionary analysis.
Why should they know about protein mis-folding?
Knowing how proteins mis-fold we can understand diseases and know how the accumulation of abnormal cleavage and glutamine develops in Alzheimer's. Also, knowing why plaques and tangles occur can help understand why and if they are actually mis-folding.
How important is the search for a cure or finding out why/how Alzheimer's happens?
This is a huge search for a cure. One has to find the answers to where are the mutations/dispositions? People are living longer so now there is a higher percentage of elderly people getting Alzheimer's. The percentages alone show that 0.1% get Alzheimer's at age 60 while at age 80 it's 10%. Also, at age 90 it is over 30%, which shows that aging may be a reason why Alzheimer's is on the rise.
What do you think about using grid computing in this search?
If it's looking at different database of proteins it can look at little differences in the folding of proteins and differences from person to person.
Are there any new means of prevention of Alzheimer's?
There are many drugs now that delay the onset of deterioration. Also, there is treatments that block the plaques, but there are certain drugs that can't cross the membrane. Oxidation reactions is looking to be treated with forms of antioxidants.
Any other interesting stories dealing with folding of proteins or Alzheimer's?
High cholesterol drugs that lower cholesterol are being looked at as a possible side effect of slowing Alzheimer's. Prions (proteins in the body) can get mis-folded and the one that is mis-folded may have the mutation that will effect the brain.
Subscribe to:
Comments (Atom)