Nathan+P

__Prader-Willi Syndrome__

Prader-Willi syndrome (PWS) is an autosomal syndrome where parts of the 15th chromosomes become inactive. People with this disorder still have the correct number of the 15th chromosomes. PWS affects both sexes and all races of humans. Of the people who have PWS, 70% get it when a part of the father's 15th chromosome is deleted while the mothers chromosome is normal(known as deletion). Of the remaining 30%, 25% goes to another inherital defect where the mother gives two chromosomes while the father gives none (known as maternal disomy), and the remaining percent goes to a small genetic mutation that cause the Prader-Willi region to become inactive (Imprinting defect). It is not a hereditary syndrome since it is caused by some form of non-disjunction of a gene and not a dominant and recessive trait.

__Symptoms__

Common characteristics and symptoms of PWS in infants include:
 * Poor muscle tone
 * Distinct facial features
 * Poor sucking reflexes
 * Lack of eye coordination
 * Unresponsiveness
 * Weak cry
 * Fair skin

Common characteristics and symptoms of PWS in early childhood through adulthood include:
 * Food Craving
 * Weight gain
 * Underdeveloped sex organs
 * Poor growth and physical development
 * Delayed motor development
 * Speech problems
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Behavioral problems
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Sleep Disorders
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Scoliosis
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Small feet and hands
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Fair skin
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Poor teeth development
 * <span style="color: #000000; font-family: 'Times New Roman',serif;">Slow metabolism

<span style="font-family: Times New Roman,serif;">__**Life**__

<span style="font-family: 'Times New Roman',serif; text-decoration: none;">If the person maintains a healthy life style he or she will have a normal life expectancy. However, if the person doesn't maintain a healthy life style they may become obese and have a shortened life span. This obesity is due to the high cravings of food and a slow metabolism. The person may also have intellectual disabilities and may develop later then other children. They may also be unable to reproduce because of the underdeveloped sex organs.

<span style="font-family: Times New Roman,serif;">__**Extra**__

<span style="font-family: 'Times New Roman',serif; text-decoration: none;">The only outside factor that could contribute to the disorder is having another child who has PWS. This factor increases the likelihood of the other children also getting the syndrome. Also, the name of the disorder comes from the names of the two Swedish doctors who discovered it in 1956.

<span style="font-family: Times New Roman,serif;">__**Statistics**__


 * <span style="font-family: 'Times New Roman',serif; text-decoration: none;">1 out of every 12000-15000 infants get PWS
 * <span style="font-family: times new roman,serif; text-decoration: none;">70% of people with PWS have a deletion of the 15th chromosomes
 * <span style="font-family: times new roman,serif; text-decoration: none;">25% of people with PWS have maternal disomy of the 15th chromosomes
 * <span style="font-family: times new roman,serif; text-decoration: none;">5% of people with PWS have Imprinting defects of the 15th chromosomes

__** Sources **__

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__**[|http://www.medicinenet.com/prader-willi_syndrome/page1.htm]**__

Book: Wolvier, Robbie. Alphabet Kids from ADD to Zellweger syndrome. 116 Pentonville Road London UK: Jessica Kingsley, 2009.print.