I found a research article about genetic effects on
Alzheimer’s in African Americans, and it was published quite recently (April 10th,
2013). This article (http://jama.jamanetwork.com/article.aspx?articleid=1677372)
looked at the different variants of genes and how these variants could lead to
Alzheimer’s. They found that variation in the ATP-Binding Cassette Transporter
gene (ABCA7) as well as some other genes increases the risk of African
Americans getting later onset Alzheimer disease (LOAD). ABCA7 has a role in
creating high-density lipoprotein from cellular lipids and helical
aplolipoproteins. ABCA7 also has a role in phospholipid and cholesterol efflux
from cells. Because variation in the ABCA7 gene increases the risk in Alzheimer’s,
it is now thought that having something wrong in lipid metabolism causes LOAD
in African Americans. However, this is not the only pathway that ABCA7 affects.
ABCA7 also affects the transport of certain proteins through the cell membrane,
and one of these proteins is the amyloid precursor protein. Another effect that
ABCA7 has is on the phagocytosis of apoptotic cells by macrophages. All of
these may provide a clue as to the etiology of Alzheimer’s.
One of the interesting points that I found in this article
was there were some genes that increased the risk of LOAD on both Caucasians
and African Americans, but there were also some genetic variations that were
found to be more significant on increasing the risk in African Americans. I
knew certain ethnicities have a higher risk for some diseases, and I had
attributed it to the different genetic makeup. However in this case, it isn’t
just the different genetic makeup that holds my attention. The fact different
genetic variations can cause Alzheimer’s means that the etiology of Alzheimer’s
for different races can also be different. If so, then treatment would also
have to depend on one’s race or patients would have to undergo genetic testing
to know what type of treatment they would need (unless these differences can be
tested elsewhere).
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ReplyDeleteI really enjoyed this blog entry on the ABCA7 gene, and Alzheimer's Disease. I found another article that related to this one: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045959 . The article mentions how crucial ABCA7 is for neurological function, and that defects might also contribute to schizophrenia. In this article the researchers investigated ABCA7 on ABCA7 knockout mice. These mice had normal sensory, and motor abilities. Another interesting part about this paper was that males and females functioned differently. For instance, male knockout mice had the greatest defects in their ability for object recognition. Meanwhile, female knockout mice had significant impairment in their spatial reference memory. The difference between males and females might cause variation in future treatment options. We know that comparing a mouse model to a human model does not always show the same results. It would be interesting to see what the differences are between gender in humans with Alzheimer's Disease.
ReplyDeleteMy favorite point in this blog was about different genetic variations causing Alzheimer's disease. It was a good point that these genetic differences between different groups would make it complicated to treat via gene therapy.
I really liked this concept and I also its interesting to see how the genetic variation in some of the races can cause the disease to be more complicated in finding a cure that can be more generalized for the entire population. I really liked learning about Alzheimer's Disease and I think more research needs to be done in this area to determine the exact mechanism of this disease and how it progress and that can help with finding a gene therapy that is effective for the entire population.
ReplyDeleteHopefully these gene studies will help reveal the underlying biological causes of Alzheirmer’s and from there new treatments or preventive measures can be developed. My family owns a group home, and over the years I’ve met a lot of seniors who have had Alzheimer’s and it is a difficult disease to deal with. They often require a lot of supervision and personal care, and emotionally and finacially can be very challenging on the families. If they were perky or sociable throughout their life they tend to keep that part of their personality, but their memory quickly declines, and so does their ability to carry a conversation. The prevalence of Alzheimer’s is only increasing in the US and without any good ways to prevent it, cure it, or slow its progression, occurring to the Alzheimer’s association the cases could triple by 2050. It is the only major disease to have increased between 2000 and 2010, and that increase was 68%. On top of that, a report by the Alzheimer's Association 2013 Alzheimer's Disease Facts and Figures released in March 19, 2013 also found that 1 in 3 seniors die from Alzheimer’s or another form of dementia, and with no known survivors it means you will either die from it or die with it. This is a global issue as well, because with family practices like in China, where they typically only have one kid, the burden to take care of your parents and your spouse’s parents can end up depending on a single income and ultimately pushing more families into poverty. Sorry for the depressing post, but I have thought about this issue before, and even the ability to prolong this disease 5 years will greatly improve the quality of life. Hopefully this discovery can be a good stepping stone to dealing with this disease.
ReplyDeleteReference:
http://www.alz.org/news_and_events_facts_and_figures_report.asp