Pku (Phenylketonuria)
Erin Quinn
NS335-0
Unit 9 Project: Marcie M.
Kaplan University
January 8, 2012
Inborn errors of metabolism are rare genetic disorders in which the body cannot metabolize certain substances in food because of a defect in specific enzymes. Treatment of IEMs is a diet change to control the substances that cannot be metabolized in order to prevent a rise in the level of the substance which can be harmful to the body. In PKU, the baby is born without the ability to properly break down an amino acid called phenylalanine which is found in foods that contain protein. Since it cannot be broken down, phenylalanine levels become dangerously high and cause severe damage to the central nervous system. PKU is passed down to an infant by both parents who are carrying the gene but may not be aware of it.
A PKU test is not done immediately after birth because the baby needs time to be able to ingest protein in order to determine if there is a problem with phenylalanine metabolism. After a few days, when the baby has eaten and has ingested protein, a PKU test can be done because there will be a more accurate outcome. Still, some tests are not 100% accurate so further blood and urine testing at 2 and 4 weeks intervals may be needed for a definite diagnosis. Just a thought - Marcie’s low birth weight puts her at risk for health problems (although she would have had PKU regardless of her birth weight since it is genetic) and makes me wonder if she may have been born before 40 weeks gestation since most babies should weigh 5.5 lbs. by week 37.
A baby who has PKU but is not diagnosed and treated within the first 2 years of life will exhibit severe developmental problems that will become irreversible. The baby will seem normal during the first few months, but as phenylalanine levels rise, the child can have seizures, will not be able to sit up, crawl, walk or talk, and will
NS335-0
Unit 9 Project: Marcie M.
Kaplan University
January 8, 2012
Inborn errors of metabolism are rare genetic disorders in which the body cannot metabolize certain substances in food because of a defect in specific enzymes. Treatment of IEMs is a diet change to control the substances that cannot be metabolized in order to prevent a rise in the level of the substance which can be harmful to the body. In PKU, the baby is born without the ability to properly break down an amino acid called phenylalanine which is found in foods that contain protein. Since it cannot be broken down, phenylalanine levels become dangerously high and cause severe damage to the central nervous system. PKU is passed down to an infant by both parents who are carrying the gene but may not be aware of it.
A PKU test is not done immediately after birth because the baby needs time to be able to ingest protein in order to determine if there is a problem with phenylalanine metabolism. After a few days, when the baby has eaten and has ingested protein, a PKU test can be done because there will be a more accurate outcome. Still, some tests are not 100% accurate so further blood and urine testing at 2 and 4 weeks intervals may be needed for a definite diagnosis. Just a thought - Marcie’s low birth weight puts her at risk for health problems (although she would have had PKU regardless of her birth weight since it is genetic) and makes me wonder if she may have been born before 40 weeks gestation since most babies should weigh 5.5 lbs. by week 37.
A baby who has PKU but is not diagnosed and treated within the first 2 years of life will exhibit severe developmental problems that will become irreversible. The baby will seem normal during the first few months, but as phenylalanine levels rise, the child can have seizures, will not be able to sit up, crawl, walk or talk, and will
References: A.D.A.M. Inc. (2011) Phenylketonuria. Retrieved on 1/9/12 at http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002150/ Discovery Communications, LLC Energy Active Ltd. (2012) Meal Plan for Phenylketonuria (PKU) – Child. Retrieved on 1/10/12 at http://www.mealplansite.com/medical-pku-child.aspx MedlinePlus MFMER (2011) Phenylketonuria (PKU). Retrieved on 1/9/12 at http://www.mayoclinic.com/health/phenylketonuria/DS00514/DSECTION=lifestyle-and-home- remedies Stanfield, P University of Washington (2008) What is the diet for PKU? Retrieved on 1/10/12 at http://depts.washington.edu/pku/about/diet.html WebMD (2010) Phenylketonuria (PKU) Test