PHENYLKETONURIA: A METABOLIC DISORDER

PHENYLKETONURIA: A METABOLIC DISORDER

Metabolic disorders are genetic diseases that affect the body's ability to perform its normal chemical reactions. Many metabolic disorders result from enzyme defects. Recall that a metabolic pathway is a stepwise sequence of enzyme-mediated reactions. If one enzyme in a metabolic pathway is defective, that enzyme's substrate may accumulate and the pathway may not be completed. This may result in a buildup of harmful substances or a shortage of required molecules.

Activity

In this exercise, you will use the Web links below to gather information about the metabolic disorder phenylketonuria (PKU). Use what you learn to answer the questions at the bottom of the page.


Your Genes, Your Health: Phenylketonuria
http://www.ygyh.org

NSPKU Home Page
http://www.nspku.org

Texas Department of Health Genetic Disorders
http://www.dshs.state.tx.us/newborn

Phenylketonuria - The Genetics
http://willroberts.com/pku/


Questions

1. What enzyme is most commonly defective in people with phenylketonuria?
        The Phenylketonuria is the most common defective enzyme. If high levels of PKU are in the brain it can cause retardation.
2. What reaction does this enzyme catalyze? (What is the substrate and what product is produced?)

3. Describe the symptoms of phenylketonuria.
         A child with Pku may have a smaller then normal head epilepsy and mental retardation. Also there skin will have a musky odor lighter color skin and hair
4. What causes the symptoms of PKU, the lack of a substance or the buildup of one?
The build up of the substance causes PKU

5. How common is phenylketonuria? How is it treated?
1 in 10,000 Caucasians some ethnic groups are higher and some ethnic groups are lower. to treat PKU the person must go on a low protein diet for life.