Module 13: Overview of Genetic Errors of Metabolism

Question 1

Phenylalanine Hydroxylase Deficiency (PKU)

Answer 1

• Phenylalanine hydroxylase (PAH) deficiency
• Autosomal recessive
• Causes buildup of phenylalanine (amino acid) due to a defect in the gene that creates the enzyme needed to break down phenylalanine

Question 2

Galactosemia

Answer 2

• Disorder of carbohydrate metabolism that affects the body’s ability to convert galactose to glucose
• Treated w/ dietary restrictions

Question 3

Familial Hypercholesterolemia (FH)

Answer 3

• Autosomal dominant
• Causes xanthoma in skin
• Causes elevated LDL cholesterol & increased risk of early onset coronary artery disease

Question 4

What body system is affected in both chronic and acute metabolic conditions?

Answer 4

Nervous system

Question 5

Why are individuals with a metabolic condition usually normal at birth?

Answer 5

The individual’s mother provides normal metabolism in utero

Question 6

What is the primary organ that is impacted by elevated phenylalanine in individuals w/ PKU?

Answer 6

Brain

Question 7

What enzyme defect is responsible for most cases of Galactosemia?

Answer 7

GALT

Question 8

What is the main component of Xanthomas?

Answer 8

Fats

Question 9

What is the primary defect in Familial Hypercholesterolemia?

Answer 9

Defective or absent LDL receptors

Question 10

What childhood condition might an infant with an undiagnosed metabolic condition be diagnosed w/ early on?

Answer 10

Failure to thrive