Down Syndrome

By: Sydney Singh

Basic Info

Down Syndrome occurs when a person has an extra copy of chromosome 21. Anybody can be affected by this disease but its chances are 1 in 1,000 so it's somewhat uncommon. You are affected by this disease when you are born.

Characteristics

Some symptoms are learning difficulties, mental retardation, characteristic facial appearance, poor muscle tone in infancy, low activity of the thyroid gland. Daily life isn't any different than someone without Down Syndrome. Although someone with Down Syndrome may encounter learning difficulties and it may be harder for them to do some physical activities. Life expectancy is about half of a normal person. So most patients life to be about 50 years old.

Examples

Causes of Down Syndrome

The mutation causing this condition is called nondisjunction. Nondisjunction happens when a pair of chromosomes fails to separate during egg (or sperm) formation. The chromosome that is effected is chromosome 21. The gene is trisomy 21.

Treatment

Some possible treatments are physical therapy or speech therapy. You can also get a surgery called corrective surgery to help your eyes. Although there is no cure for this condition.

Other Facts

* In 90% of trisomy 21 cases, the additional chromosome comes from the mothers egg rather than the fathers sperm.

* Down Syndrome occurs in every 691 live births

*Most frequently occurring chromosomal disorder

*Down Syndrome is identified at birth

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Bibliographies

http://www.genome.gov/10001204
http://www.nlm.nih.gov/medlineplus/healthtopics_a.html http://learn.genetics.utah.edu/content/disorders/whataregd/