Chromosomal Disorders are errors in the copying DNA in cells, that are then repeated over and over again throughout the body, causing multiple varieties of diseases or disabilities. Often a symptom of these disorders is delayed development and handicapped mental abilities. For example, Down syndrome, which is caused by an extra copy of the 21st chromosome, causes a slight deformity in the face, slower motor skills, and delayed mental development. Down syndrome is caused by a nondisjunction event, when a chromosome fails to separate while the sperm and egg are forming into a zygote. Interestingly, down syndrome is the only trisomy that is compatible with life, whereas babies with trisomy 13 and 18 have a 1% chance of living beyond 1 year (Down Syndrome 2015). Another example of a chromosomal disorder is Cri-du-chat (cry of the cat), whose name refers to the distinctive cry of children afflicted with this disorder (Cri-du-Chat Syndrome 2015). This disorder is different from Down Syndrome in that its caused by a deletion on chromosome 5, rather than a duplicated chromosome (Cri-du-Chat 2015).
The topic of chromosomal disorders is very interesting to me because it seems like an issue that could potentially be solved in the future with advancements in science. While currently a widespread issue that afflicts millions of people across the world, future technologies could potentially eliminate this malady, giving people a chance at a normal life. Although I do not currently know very much about the intricacies of chromosomal disorders, this is a field that I could potentially be interested in researching further and learning more about. What do you think about the future of chromosomal disorders? Will there ever be a way to ensure the health of babies, even shortly after they are conceived? If so, when do you think it will be widely available?
References:
Cri-du-Chat Syndrome. (2015, January 1). Retrieved February 24, 2015, from http://learn.genetics.utah.edu/content/disorders/chromosomal/cdc/
Down Syndrome. (2015, January 1). Retrieved February 25, 2015, from http://learn.genetics.utah.edu/content/disorders/chromosomal/down/
biology is better than physics 
I found your article really interesting because I also did an article on down’s syndrome, however we talked about completely different topics on that matter. You talked about how you thought that down’s syndrome could be potentially solve din future advancements in science, which is what my blog was about. I talked about the two new possible breakthroughs that have happened in the Down’s Syndrome world. One being Professor Jeanne Lawrence surprising the third chromosome in test tube cells and in petri dishes which helped correct the patterns of growth in those cells. Dr. Lawrence had said that her breakthrough could be a way to help identify new drugs to help Down’s Syndrome. Another breakthrough was Professor Roger Reeves who was able to use mice who had similar down syndrome like compounds and he was able to normalize the cerebellum’s growth which therefore helped the mice with their learning and memory which are both problems for people who have down’s syndrome. I also have never heard of cri-du-chat, but it was interesting on how different mutations could affect a person. I hope and agree with you that with time, future advancements in science could create a possibility for a cure for these diseases.
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I think you had some interesting points about all of these different types of chromosomal disorders. Obviously, all types of chromosomal disorders are very bad and detrimental to someone’s health, however, the one chromosomal disorder I want to focus on is Down Syndrome (with the alteration of chromosome 21). The reason is that when you ask in your article “is there a way to ensure the health of babies and their future”, this really only applies to trisomy-21 right now (seeing the fact that if you look towards other chromosomal disorders, most duplications allow the baby to live 1 year at the most). People on the other hand, can live with trisomy-21 for their entire life. An interesting article came up when I was researching possible cures or treatments for Down Syndrome and I think that you might find interesting as to answer your aforementioned question.
Researchers and scientists at the University of Washington have recently been successful in gene therapy in a laboratory setting. Using cell cultures derived from a person with Down Syndrome, the scientists were able to remove the extra chromosome 21 (Gray 2012). Though Dr. Li admits that he and his team is not ready to release this as a widespread treatment of the disease, he says that the implications are enormous (Gray 2012). For specific diseases like blood-forming disorders, Dr. Li thinks that this revolutionary treatment could be given to patients to salvage some of the symptoms people with Down Syndrome show (Gray 2012). For instance, he states “someday Down syndrome leukemia patients might have stem cells derived their own cells, and have the trisomy corrected in these lab-cultured cells. They could then receive a transplant of their own stem cells – minus the extra chromosome – or healthy blood cells created from their fixed stem cells and that therefore don’t promote leukemia, as part of their cancer care” (Gray 2012).
More specifically, I was also interested in the actual method in which the doctors were able to get rid of the extra 21st chromosome. So first, the scientists used an adenovirus to actually deliver the gene to the chromosome 21 (Gray 2012). The gene that they delivered was called TKNEO, where it was delivered onto the APP site of the 21st chromosome. After this, the scientists fed the cell cultures with a variety of mediums (Gray 2012). The mediums that were harmful to the TKNEO’s had a cell response of shutting off the chromosome with the TKNEO gene on it, also bringing with it an entire loss of the chromosome, leaving behind nothing (Gray 2012). This was extremely beneficial and promising because not only were there no fragments left behind, but also for the cell to survive, it responded by shutting and destroying the 21st chromosome, so that now the cell had the normal amount of chromosomes (Gray 2012). Another way in which the cell responded to survive such circumstances was to alter DNA base pairs so that TKNEO turned off, and thus the entire chromosome would be deleted (Gray 2012).
Ultimately, I think that the use of gene therapy could be key to the breakthrough in terms of cures and treatments for the prevalent disease of trisomy-21. With the technology that we have today, I think that in the near future, it is possible for us to find a better treatment for chromosomal diseases like Down Syndrome.
References:
Gray, L. (2012, November 8). Extra chromosome 21 removed from Down syndrome cell line. Retrieved March 2, 2015, from http://www.washington.edu/news/2012/11/08/extra-chromosome-21-removed-from-down-syndrome-cell-line/
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You pose an interesting question about the future of treating chromosomal abnormalities. I think it is hard to tell, especially with my limited knowledge of the research being done on this topic, when scientists fully understand the complexities of disorders like Trisomy 21. I addition, I think that without substantial knowledge on techniques like removing duplicate or adding new chromosomes, which seems so difficult, we wouldn’t be able to fix these problems. However, I would assume that these changes, or at least the idea of helping those with these abnormalities, should come when he/she is in the first stages of development. The earlier the better, as that means less cells to work with when changing the genetic makeup of an afflicted person.
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We’ve talked about the possibility of cures in the future for chromosomal disorders such as down syndrome and other chromosomal and genetic defects in class. Although our current technology is primitive, I know there have been reported cases where doctors were able to modify the genes of the afflicted and create normal healthy genes, curing said person of their illness. While we also talked about the low success rate and the dangerous side effects, I still feel that this research should be pushed and prioritized. Gene therapy is a revolutionary new method that has way more potential impacts than just curing these disease. Imagine what we could do if we could change any gene in the human body at will, being able to modify the code to our livelihood, where we can choose to become who we are.
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