Health Promotion and Maintenance Q 93
A new mother has some questions about phenylketonuria (PKU). Which of the following statements made by a nurse is not correct regarding PKU?
A. A Guthrie test can check the necessary lab values
B. The urine has a high concentration of phenyl pyruvic acid
C. Mental deficits are often present with PKU
D. The effects of PKU are reversible
Correct Answer: D. The effects of PKU are reversible.
Phenylketonuria (PKU) is an inherited disorder that increases the levels of phenylalanine (a building block of proteins) in the blood. If PKU is not treated, phenylalanine can build up to harmful levels in the body, causing intellectual disability and other serious health problems. The signs and symptoms of PKU vary from mild to severe. The most severe form of this disorder is known as classic PKU. Infants with classic PKU appear normal until they are a few months old. Without treatment, these children develop a permanent intellectual disability. Seizures, delayed development, behavioral problems, and psychiatric disorders are also common. Untreated individuals may have a musty or mouse-like odor as a side effect of excess phenylalanine in the body. Children with classic PKU tend to have lighter skin and hair than unaffected family members and are also likely to have skin disorders such as eczema. The effects of PKU stay with the infant throughout their life (via Genetic Home Reference).
Option A: The Guthrie test as a bacterial inhibition assay was formerly used, but now being replaced by tandem mass spectrometry. The Guthrie test, also called the PKU test, is a diagnostic tool to test infants for phenylketonuria a few days after birth. To administer the Guthrie test, doctors use Guthrie cards to collect capillary blood from an infant’s heel, and the cards are saved for later testing.
Option B: Phenylalanine is present in high concentrations in the urine because of its increased build up in the body. In addition to its role in protein production, phenylalanine is used to make other important molecules in the body, several of which send signals between different parts of the body. Phenylalanine has been studied as a treatment for several medical conditions, including skin disorders, depression, and pain
Option C: Without treatment, children affected with PKU develop a permanent intellectual disability. Seizures, delayed development, behavioral problems, and psychiatric disorders are also common. Untreated individuals may have a musty or mouse-like odor as a side effect of excess phenylalanine in the body. Children with classic PKU tend to have lighter skin and hair than unaffected family members and are also likely to have skin disorders such as eczema.