Sunday, 12 October 2014

Down Syndrome

Healing Down Syndrome

     There is finally a cure for Down Syndrome! The article from the Scientific American described the new drug that annuls the effects of the Down Syndrome. The Down Syndrome has been considered an incurable developmental delay. Scientists have come up with a drug that effects the cerebellum (figure 1 illustrates the brain and shows the location of the cerebellum), part of the brain, and restores all of its imperfections. However, the drug has only been tested on mice with Down Syndrome. The cerebellum is in charge for the body's motor functions, motor learning and balance and is 40% smaller than normal in mice with Down Syndrome. The drug stimulates an important neurodevelopmental pathway that increases the size of the cerebellum. After taking the drug, the Down Syndrome mice could find their way out of a water maze. This could mean that the drug either fixed both the cerebellum and the hippocampus, or the hippocampus is responsible for more that we thought. As far as scientists know, the hippocampus (Figure 2 illustrates the position of the hippocampus) is responsible for learning and memory.


               (Figure 1) The cerebellum is the the
               lowest part of the brain responsible for                              
               body's motor functions, motor learning                            
               and balance                                                                        (Figure 2) The hippocampus                                                                                                                     of the brain serves for learning and                                                                                                           memory                                          
     According to Wikipedia, the Down Syndrome is a genetic disorder that is characterized by an extra 21st chromosome, hence the name Trisomy 21 (Figure 3 shows the karyotype of a person with Down Syndrome). It occurs when a chromosome does not separate correctly during anaphase and one gamete ends up with two copies of the 21st chromosome. That leads to all the cells having an extra chromosome, which creates serious consequences afterwards. After birth, the development is slowed down, so they never completely physically and mentally mature. People with Down Syndrome are mentally retarded and have certain physical traits that vary from the normal. For example, they usually have shortened hands, short necks, low muscle tone etc. Also, their facial characteristics include abnormal teeth, slanted eyes, a flattened face, a small but wide nose, small earlobes, etc. (Figure 4 clearly shows the facial characteristics of a child with Down Syndrome) The Down syndrome is also connected with cardiac and gastrointestinal defects that can result in premature death.The average IQ of an adult with Down Syndrome usually ranges around 50, (±10),  which is the average IQ of an 8 year old, but can go as low as 20, or as high as 70, but that is still low compared to the average IQ of an adult, which is 90-109.  The individuals that suffer from this syndrome live harder lives, for they have an intellectual and physical handicap. Because of their low IQ, they can't get jobs that require university. Also, they can't get jobs that require physical strength or endurance, like being professional athletes, artisans or builders because of the low muscle tone. A hundred years ago, life expectancy of people with Down Syndrome was only 12, but today it is 5 times larger, they can live to be 60. This disorder is fairly common, for it appears once in a thousand births. In live born children, it is the most common genetic anomaly. The child's genetic health is highly dependant on the woman's age. If a woman is 20, the likelihood of her child being born with Down syndrome is 1:1500, but at the age of 45 the likelihood increases to 1:30. The association between Trisomy 21 and the maternal age has nothing do with race, social and economic factors and geography. But how do you stop the appearance of  the Down Syndrome?  For diagnosing Down syndrome, trisomy 18 and the neural tube defect, a non invasive triple screen test is used. If the test is positive, then amniocentesis is done. An amniocentesis is the removal of a part of the amniotic fluid from the maternal gravid abdomen so the genetic material of the fetus can be sampled. For pregnant women older than 35 a triple test is not enough, but an amniocentesis is required. A karyotype has to be made during the second trimester of pregnancy, and if the doctors determine that the baby has Down syndrome, it is suggested that the mother gets an abortion.

(Figure 3) This is a karyotype of a person with                                      (Figure 4) This photo shows Trisomy 21                                                                                              facial characteristics of a child                                                                                                                  with Down syndrome

     The story is very important not just for people suffering from Down Syndrome whose abilities would be repaired, but also through many other aspects. The quality of life of the people with Trisomy 21 would improve too, because their intelligence and motor abilities would increase. Then they could take part in normal social activities. They could also have a larger variety of jobs to choose from, because they would be able to seek a higher education. This would also make their parents lives much easier, for the children would live normal lives and be independent when they grow up. Costs for nursing and care of Down syndrome people would be significantly reduced. 


  1. Very good, it was written very nicely, but I think that you shouldn't have so much about the disorder and you should incorporate it better with the article. the pictures were appropriate and were labeled.

  2. I liked how you explained all the scientific terms and kept it interesting and easy to understand. I liked that your pictures connect well to the text. Nice work :)

  3. Good job this was well written, you explained in a great detail about the disorder and all the scientific terms. However I think you should have written more about the story itself.


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