Deck 25: Metabolic Disorders

Question 1

People with PKU can have a musty or mousy smell due to phenylketones accumulating where?

A) breath
B) sweat
C) ear wax
D) feces
E) urine

Answer 1

E

Question 2

Which amino acid disorder affects the metabolism of methionine?

A) homocystinuria
B) phenylketonuria
C) tyrosinemia
D) isovaleric acidemia
E) maple syrup urine disease

Answer 2

A

Question 3

Which trisaccharide is not digested by humans?

A) maltose
B) glucagon
C) raffinose
D) ribose
E) amylopectin

Answer 3

C

Question 4

Which type of glycogen storage disease is characterized by a deficiency of lysosomal acid alpha-glucosidase?

A) type III
B) type IV
C) type V
D) type II
E) type VI

Question 5

Which amino acid is affected in the metabolic disorder isovaleric acidemia?

A) valine
B) tryptophan
C) leucine
D) isoleucine
E) arginine

Question 6

Which chemical compound is used to scavenge excess ammonia from the bloodstream?

A) sodium benzoate
B) sodium carbonate
C) potassium iodide
D) calcium chloride
E) sodium alginate

Question 7

3-methylcrotonylglycinuria is a metabolic disorder of which branched-chain amino acid?

A) valine
B) isoleucine
C) leucine
D) tryptophan
E) arginine

Question 8

Which amino acid is affected in the metabolic condition maple syrup urine disease?

A) methionine
B) serine
C) isoleucine
D) phenylalanine
E) cysteine

Question 9

What is a common neurologic sign of inborn errors of metabolism in neonates?

A) seizures
B) hyperpnea
C) tachypnea
D) vomiting
E) ectopia lentis

Question 10

Which of the following is an insoluble component of starch?

A) carnitine
B) glucagon
C) raffinose
D) ribose
E) amylopectin

Question 11

How many metabolic disorders can be screened for at a time using tandem mass spectroscopy?

A) 110
B) over 80
C) 58
D) over 30
E) 15

Question 12

Which amino acid is affected in the metabolic condition phenylketonuria (PKU)?

A) methionine
B) leucine
C) tryptophan
D) phenylalanine
E) cysteine

Question 13

Which of the following statements is true of the amino acid disorder homocystinuria?

A) Cysteine is not converted to homocysteine.
B) Homocysteine is not converted to cysteine.
C) Homocysteine is not converted to lysine.
D) Homocysteine is not converted to leucine.
E) Cysteine is not converted to valine.

Question 14

Which amino acid supplement used for metabolic disorders displays antiatherogenic, antioxidant, and immunomodulatory properties?

A) valine
B) isoleucine
C) leucine
D) tryptophan
E) arginine

Question 15

What is the term used to refer to the variation in the presentation of metabolic disorders?

A) variant
B) genotype
C) haplotype
D) phenotype
E) degree

Question 16

Which vitamin, in pharmacological amounts, is used for the treatment of vitamin-responsive forms of methylmalonic acidemia?

A) biotin
B) vitamin B12
C) vitamin B6
D) riboflavin
E) vitamin C

Question 17

How are most inborn errors of metabolism acquired?

A) autosomal dominant inheritance
B) autosomal recessive inheritance
C) infection
D) dietary deficiency
E) blood toxicity

Question 18

What is a common secondary consequence of metabolic defects?

A) bacterial infections
B) nutritional deficiencies
C) arthritis
D) cancer
E) autoimmune disorders

Question 19

What is the targeted blood Phe range, as recommended in the new ACMG guidelines, for all individuals with PKU?

A) 20-30 μmol/L
B) 65-105 μmol/L
C) 120-360 μmol/L
D) 400-600 μmol/L
E) 650-820 μmol/L

Question 20

What is the term used for a substrate needed for the normal metabolism of fat for energy?

A) carnitine
B) glucagon
C) raffinose
D) ribose
E) amylopectin

Question 21

PD is an 11-month-old boy with phenylketonuria (PKU). His mother brought him to an outpatient nutrition center in the local pediatric hospital for evaluation.
Length: 28 inches Weight: 19 pounds (8.7 kg)
What are PD's daily protein needs?

A) 32 g
B) 31.4 g
C) 30 g
D) 28.3 g
E) 24 g

Question 22

Which vitamin supplement is used as a treatment for the holocarboxylase synthetase deficiency disorder?

A) thiamin
B) riboflavin
C) biotin
D) niacin
E) folic acid

Question 23

Which vegetable oil has the highest amount of linolenic acid?

A) flaxseed
B) safflower
C) corn
D) peanut
E) olive

Question 24

How many enzymes are needed to convert fructose into intermediates of the glycolytic gluconeogenic pathway?

A) one
B) two
C) three
D) four
E) five

Question 25

Which of these is a predominant dietary source of galactose?

A) fructose from fruit
B) lactose from milk
C) glucose from honey
D) glycogen from meat
E) fiber from vegetables

Question 26

Which of the following drugs binds with homocysteine to form the amino acid methionine?

A) metronidazole
B) cystadane
C) amoxicillin
D) cyclosporine
E) tacrolimus

Question 27

Which vegetable oil contains the highest amount of linoleic acid?

A) flaxseed
B) safflower
C) corn
D) peanut
E) canola

Question 28

PD is an 11-month-old boy with phenylketonuria (PKU). His mother brought him to an outpatient nutrition center in the local pediatric hospital for evaluation.
Length: 28 inches Weight: 19 pounds (8.7 kg)
Phe restriction should achieve optimal blood Phe levels of:

A) 20-30 μmol/L
B) 65-105 μmol/L
C) 120-360 μmol/L
D) 400-600 μmol/L
E) 650-820 μmol/L

Question 29

What is the most predominant type of mitochondrial disorder?

A) fatty acid transport disorders
B) fatty acid oxidation defects
C) glycogen complex disorders
D) respiratory chain disorders
E) pyruvate complex disorders

Question 30

PD is an 11-month-old boy with phenylketonuria (PKU). His mother brought him to an outpatient nutrition center in the local pediatric hospital for evaluation.
Length: 28 inches Weight: 19 pounds (8.7 kg)
What two common PKU characteristics did PD's mom likely notice in her son?

A) fair complexion and musty-smelling urine
B) dark skin pigmentation and foul breath
C) bowed legs and high-pitched screeching
D) bloody diarrhea and muscle paralysis
E) severe insomnia and fatty stool

Question 31

What type of fatty acids are linoleic and linolenic acids?

A) short-chain
B) medium-chain
C) long-chain
D) very long-chain
E) polysaccharide

Question 32

Which enzyme deficiency results in the accumulation of fructose-1-phosphate?

A) glucokinase
B) arginase
C) phenylalanine hydroxylase
D) lipase
E) aldolase B

Question 33

What is the function of riboflavin and thiamin in the respiratory chain?

A) antioxidants
B) cofactors
C) artificial electron receptors
D) artificial electron transporters
E) antivirals

Question 34

Which amino acid is affected in the metabolic disorder 3-hydroxyisobutyric aciduria?

A) valine
B) tryptophan
C) leucine
D) isoleucine
E) arginine

Question 35

Fructose-induced hypoglycemia results from inhibition of gluconeogenesis and which other process?

A) glucogenesis
B) glycogenesis
C) the chaperoning effect
D) glycolysis
E) glycogenolysis

Question 36

PD is an 11-month-old boy with phenylketonuria (PKU). His mother brought him to an outpatient nutrition center in the local pediatric hospital for evaluation.
Length: 28 inches Weight: 19 pounds (8.7 kg)
What is the maximum total amount of phenylalanine that PD can consume every day?

A) 168.5 mg
B) 246 mg
C) 304.5 mg
D) 391 mg
E) 451.5 mg

Question 37

Which of the following diets is recommended for a patient with a hereditary deficiency of the enzyme aldolase B?

A) sucrose-rich diet
B) fiber-free diet
C) omega-3 fatty acid-free diet
D) sorbitol-rich diet
E) fructose-free diet

Question 38

PD is an 11-month-old boy with phenylketonuria (PKU). His mother brought him to an outpatient nutrition center in the local pediatric hospital for evaluation.
Length: 28 inches Weight: 19 pounds (8.7 kg)
What are PD's daily caloric needs?

A) 1,151 kcal
B) 1,022 kcal
C) 986 kcal
D) 914 kcal
E) 845 kcal

Question 39

In addition to classic galactosemia, what are the other two variants of galactosemia?

A) Duarte and Black
B) variant I and variant II
C) Edwards and Jackson
D) dairy and fruit
E) secondary and tertiary

Question 40

Which type of glycogen storage disease causes a muscle phosphorylase deficiency?

A) type II
B) type III
C) type IV
D) type V
E) type VI

Question 41

Tandem _______________ allows clinicians to screen for over 30 metabolic disorders by analyzing metabolites in a blood spot collected on a filter paper from a simple heel prick on the newborn.

Question 42

Galactose is a monosaccharide found in milk products; galactosemia may be rapidly fatal in infants if milk feedings are not discontinued.

Question 43

Urea cycle disorders result in an impaired capacity of the body to excrete nitrogen in the form of urea.

Question 44

Pharmaceutical products such as sodium ________________ and sodium phenylbutyrate are needed to remove the excess nitrogen that is produced as a result of a block in the urea cycle.

Question 45

Impaired metabolism of nutrients can be caused by a defective gene that results in a change to the binding site of cofactors.

Question 46

The deficiency or absence of the phenylalanine _______________ enzyme leads to the inability to convert the essential amino acid phenylalanine into the amino acid _______________.

Question 47

In glycogen storage disease type III, protein is used as an alternative source of glucose production, via the _______________ shunt.

Question 48

Isovaleric acidemia (IVA) is an amino acid disorder affecting the metabolism of multiple amino acids.

Question 49

Mitochondria are found in every cell in the human body.

Question 50

_______________ is used to remove and detoxify waste products that accumulate in organic acid disorders affecting the metabolism of proteins, carbohydrates, and/or fats.

Question 51

Skin lymphocytes or peripheral blood fibroblasts can be used to determine the extent of enzymatic activity present.

Question 52

Fatty acids must be taken into the mitochondria using the leucine transport system.

Question 53

Inhibition of both _______________ and glycogenolysis results in fructose-induced hypoglycemia.

Question 54

Untreated _______________ can cause neurologic abnormalities, seizures, and eczema.

Question 55

Neonates with a metabolic disorder generally show acute central nervous system symptoms, including generalized or partial _______________.

Question 56

The genetic defect in phenylalanine hydroxylase leads to a reduction in or an absence of phenylalanine hydroxylase activity.

Question 57

The detection of inborn errors of metabolism is complicated by the fact that many symptoms are nonspecific and can be similar from one inborn error of metabolism to the next.

Question 58

In an autosomal recessive disorder, carrier parents have a _______________% chance of having an affected child with each pregnancy.

Question 59

Selective neonatal screening is the testing of an individual known to be at increased risk for a _______________ disorder.

Question 60

Additional amounts of a cofactor can provide for a chaperoning effect where the cofactor helps to stabilize the enzyme complex, allowing for an increase in enzyme activity.

Question 61

Discuss the epidemiology of amino acidopathies.

Question 62

Organic acidemias are a subset of _______________ disorders that involve a dysfunction in the metabolism of intermediary products.

Question 63

Describe how clinicians screen for multiple metabolic disorders in infants.

Question 64

Fatty acids in the mitochondria are converted to ketone bodies by the process of _______________.

Question 65

Describe the etiology of urea cycle disorders.

Question 66

Describe supplementation of end products as an approach for chronic management of metabolic disorders, and provide a specific example.

Question 67

In patients with galactosemia, the enzyme defect occurs in uridyltransferase, which normally converts galactose, in the form of galactose-1-phosphate, to _______________.

Question 68

Describe the acute nutritional interventions used for urea cycle disorders.

Question 69

Describe the use and benefits of sapropterin dihydrochloride.

Question 70

The urea cycle resides primarily in the _______________, but this process can also take place to a lesser extent in the kidneys and small intestine.

Question 71

Some of the galactose in fruits and vegetables may be found as the galactose _______________, raffinose and stachyose, and hence is most likely unavailable for absorption.

Question 72

A pharmacologic dose of vitamin B₁₂is given to a newly diagnosed patient with _______________ acidemia to determine whether the enzymatic defect is vitamin responsive.

Question 73

Describe the causes, symptoms, and incidences of galactosemia.

Question 74

Glycogen storage disease type I (GSD I) is characterized by a deficiency of the enzyme _______________.

Question 75

Carnitine is usually supplemented if the amount of free carnitine is _______________ and/or the ratio of esterified to free carnitine is _______________.

Question 76

Sapropterin dihydrochloride is an oral formulation of the biologically active tetrahydrobiopterin, cofactor to the _______________ enzyme.

Question 77

Describe the acute nutritional interventions used for disorders of fat metabolism.

Question 78

Explain how fructose is normally metabolized.

Question 79

Define the alanine shunt. In what disease is it used?

Question 80

Mitochondria are essential for the production of _______________ in all types of tissues.