Down syndrome is caused by the presence of an extra chromosome 21. It is neither dominant nor recessive as it results from an error in chromosome translation. The amyloid precursor protein gene on chromosome 21 may cause Down syndrome by interfering with cell signaling and leading to cell death. People with Down syndrome have distinct physical features like a flattened face and webbed fingers or toes. Treatments focus on managing any related health issues and providing early intervention programs. Life expectancy is around 50 years on average.

1. Down Syndrome By: Karry Emretiyoma Pavel Stolarczyk A-4

2. Basic Info Down syndrome is an autosomal disorder because it affects chromosome 21 which is an autosome. Down syndrome is neither a dominant nor recessive trait because it is just an error in the translation process of chromosome 21.

3. Gene Scientists believe that the gene that may be the cause of down syndrome is the amyloid precursor protein gene (App) which is located on chromosome 21. A mutation in this gene usually results in Alzheimer’s disease but three copies of the gene has a huge effect on the brain. Scientists believe that App is causing the cells to die because it interfers with the signaling between these cells that is needed to keep them healthy. This may be why people with down syndrome tend to develop the brain signs of Alzheimer’s.

4. Symptoms People with down syndrome have very distinct characteristics and features than people without the disorder. These include: Webbed fingers and toes Flattened nose and face Stubby fingers. Rounded nose and face

5. Treatment Some kids may need certain surgeries soon after birth to keep them from dying. Some children don’t have many medical problems and can live a healthier life. At birth ultrasounds of children are made to look for congenital heart diseases.

6. Other Treatments Medications can be used to treat certain health conditions that are caused by down syndrome. Medicines that may help with seizure disorders or thyroids. Children with down syndrome will be placed in early intervention programs which is a program that was made to specifically help people with down syndrome.

7. Impact on Living People have trouble speaking. Slurred speech. Some people with Down Syndrome have plastic surgery so their body looks different. Some people with down syndrome also face other life threatening medical problems such as heart defects, thyroids, and hearing problems All of these medical problems really add strain to the life of a person with down syndrome.

8. Other Information People with down syndrome live up to about 50 years old. In 90% of Trisomy 21 cases, the additional chromosome comes from the mother's egg rather than the father's sperm. Down syndrome affects 1 out of every 800 to 1,000 babies Down syndrome was originally described in 1866 by John Langdon Down. It wasn't until 1959 that a French doctor, named Jerome Lejeune, discovered it was caused by the inheritance of an extra chromosome 21.

9. Pedigree This is a pedigree of a family with down syndrome in its generations.

10. For More Information For more information about down syndrome check out these websites! http://www.nichd.nih.gov/health/topics/Down_Syndrome.cfm http://films.nfb.ca/tying-your-own-shoes/

11. Works Cited 1.http://learn.genetics.utah.edu/content/disorders/whataregd/down/ 2.http://films.nfb.ca/tying-your-own-shoes/ 3.http://www.nichd.nih.gov/health/topics/Down_Syndrome.cfm http://www.google.com/imgres?imgurl=http://scicarlyrae.files.wordpress.com/2011/02/pedigree1.png&imgrefurl=http:// http://news.bbc.co.uk/2/hi/health/5151232.stm