Clinical Chemistry 1: Amino Acids and Proteins Lecture

What are the high levels of phenylalanine and some of its metabolites associated with in patients with PKU?

significant brain problems

What is the characteristic odor of the urine in patients with PKU?

musty

What can be the result of toxic effects of phenylalanine or its metabolic byproducts in the brain?

mental retardation and microcephaly

What are the phenylalanine levels in patients with non-PKU mild hyperphenylalaninemia?

180-600 μmol/L Signup and view all the answers

What can be avoided if the disease is detected at birth and the infant is maintained on a diet containing low levels of phenylalanine?

brain damage Signup and view all the answers

What is the deficiency in the enzymes needed for the synthesis of tetrahydrobiopterin associated with in PKU cases?

hyperphenylalaninemia Signup and view all the answers

What is the goal of PKU treatment in terms of maintaining the blood level of phenylalanine?

2-10 mg/dL or 120-160 μmol/L Signup and view all the answers

What is the first drug to manage PKU?

Kuvan (sapropterin dihydrochloride) Signup and view all the answers

What test allows for the early detection and implementation of treatment for PKU?

newborn screening test Signup and view all the answers

What color does the urine turn when treated with ferric chloride in the urine test for PKU?

permanent bluegreen Signup and view all the answers

What is the estimated occurrence of phenylketonuria (PKU)?

1 in every 15,000 births Signup and view all the answers

What causes phenylketonuria (PKU)?

Phenylalanine hydroxylase (PAH) deficiency Signup and view all the answers

What is the consequence of phenylalanine hydroxylase (PAH) deficiency?

Disruption in the normal conversion of phenylalanine to tyrosine Signup and view all the answers

What are the phenylalanine levels in newborns with untreated classic PKU?

Greater than 1,200 μmol/L Signup and view all the answers

What is the normal phenylalanine level in newborns?

Less than 120 μmol/L Signup and view all the answers

What is the problem in aminoacidopathies?

An enzyme defect that inhibits the body’s ability to metabolize certain amino acids Signup and view all the answers

Where do abnormalities exist in aminoacidopathies?

In the activity of a specific enzyme in the metabolic pathway or in the membrane transport system for amino acids Signup and view all the answers

Name some disorders covered in aminoacidopathies.

Phenylketonuria (PKU), tyrosinemia, alkaptonuria, maple syrup urine disease (MSUD), isovaleric acidemia, homocystinuria, citrullinemia, arginosuccinic aciduria, and cystinuria Signup and view all the answers

What is the consequence of untreated classic PKU in terms of phenylalanine levels?

As high as 1,200 μmol/L Signup and view all the answers

What is the problem in phenylketonuria (PKU) due to the deficiency of the enzyme phenylalanine hydroxylase?