Deck 8: Urine Screening for Metabolic Disorders

Question 1

All of the following disorders are caused by defects in the phenylalanine-tyrosine pathway except:

A) Alkaptonuria
B) Hartnup disease
C) Tyrosyluria
D) PKU

Answer 1

B

Question 2

The presence of argentaffin cell tumors can be detected by the presence in the urine of:

A) 5-HIAA
B) Melanin
C) Homogentisic acid
D) Serotonin

Answer 2

A

Question 3

The presence of maple syrup urine disease is first suspected by the presence of abnormal urine:

A) Color
B) Protein
C) Odor
D) Amino acids

Answer 3

C

Question 4

A disease that causes large amounts of branched-chain amino acids to be excreted in the urine is:

A) Hurler syndrome
B) Cystinuria
C) Maple syrup urine disease
D) Alkaptonuria

Question 5

A urinalysis and a dinitrophenylhydrazine (DNPH)test are performed on an infant who is failing to thrive.If the DNPH test is positive,what result in the urinalysis will also be positive?

A) Ketones
B) Glucose
C) Protein
D) Bilirubin

Question 6

Types of organic acidemias can include all of the following except:

A) 5-HIAA
B) Isovaleric
C) Propionic
D) Methylmalonic

Question 7

A positive Guthrie test is interpreted by observing:

A) Bacterial growth occurs around the positive control disc and the patient disc
B) Bacterial growth occurs around the positive control disc but not around the patient disc
C) No bacterial growth occurs around either disc
D) Bacterial growth occurs only around the negative control disc

Question 8

Initial screening for PKU performed on newborns before their discharge from the hospital uses a blood sample rather than a urine sample because:

A) Urine samples are more difficult to collect
B) Serum bilirubin levels are routinely measured on all newborns
C) It is easier to measure phenylalanine than phenylpyruvic acid
D) Increased serum phenylalanine can be detected earlier

Question 9

Patients who have unusually fair complexions can be indicative for phenylketonuria because:

A) Phenylalanine is not produced
B) Tyrosine is not available for conversion to melanin
C) Melanin is converted to homogentisic acid
D) Phenylalanine disrupts liver function

Question 10

Urine with the characteristic odor of "sweaty feet" and a positive ketone test indicates:

A) Cystinuria
B) Alkaptonuria
C) Isovaleric acidemia
D) Tyrosyluria

Question 11

Accumulation of large amounts of homogentisic acid in the urine is the result of which of the following disorders?

A) Alkaptonuria
B) Tyrosyluria
C) PKU
D) Homocystinuria

Question 12

Which of the following foods contains serotonin,which can interfere with 5-HIAA testing?

A) Apples
B) Pineapples
C) Watermelon
D) Oranges

Question 13

A false-positive reaction for urinary ketones could be present in patients who have:

A) Maple syrup urine disease
B) PKU
C) Melanuria
D) Organic acidemia

Question 14

The finding of persistent ketonuria in a newborn is:

A) Of no significance
B) Indicative of juvenile diabetes mellitus
C) Associated with methylmalonic aciduria
D) Seen with severe lead poisoning

Question 15

Phenylketonuria is caused by:

A) Excessive ingestion of milk products containing phenylalanine
B) Inability to metabolize tyrosine
C) Lack of the enzyme phenylalanine hydroxylase
D) A mousy odor in the urine

Question 16

Under normal conditions,tryptophan that is not reabsorbed in the intestine is removed from the body as:

A) Indican in the urine
B) Indole in the liver
C) Indole in the feces
D) Serotonin in the urine

Question 17

Confirmation of maple syrup urine disease is made on the basis of:

A) Urine color
B) A positive 2,4-dinitrophenylhydrazine test
C) A positive ferric chloride test
D) MS/MS

Question 18

A positive urine Clinitest reaction can be seen in patients with:

A) Alkaptonuria
B) Melanuria
C) Cystinuria
D) Tyrosyluria

Question 19

A routine urinalysis is performed on a specimen that has turned dark after standing in the laboratory.The urine is acidic and has negative chemical tests except for the appearance of a red color on the ketone area of the reagent strip.One should suspect:

A) PKU
B) Diabetic ketosis
C) Alkaptonuria
D) Melanuria

Question 20

In patients with alkaptonuria,the abnormal metabolite that is present in the urine is:

A) Homogentisic acid
B) Alkaptonpyruvate
C) Phenylpyruvate
D) Tyrosine

Question 21

All of the following are primary porphyrins except:

A) Uroporphyrin
B) Porphobilinogen
C) Protoporphyrin
D) Coproporphyrin

Question 22

Chemical screening tests for cystine can produce false-positive results in the presence of urinary ketones because:

A) Cystine is not reduced by sodium cyanide
B) Cystine should be tested using only chromatography
C) The test reagent is nitroprusside
D) Cystinuria causes diabetic ketosis

Question 23

All of the following porphyrin compounds will exhibit fluorescence under ultraviolet light except:

A) Protoporphyrin
B) Uroporphyrin
C) Coproporphyrin
D) Porphobilinogen

Question 24

All of the following porphyrin compounds can be found in urine except:

A) Aminolevulinic acid
B) Coproporphyrin
C) Protoporphyrin
D) Uroporphyrin

Question 25

Urine from a child suspected of having lead poisoning has a red fluorescence under Wood's lamp.This finding is:

A) Inconsistent with lead poisoning because porphobilinogen does not fluoresce
B) Consistent with lead poisoning because coproporphyrin fluoresces under ultraviolet light
C) Consistent with lead poisoning only if uroporphyrin is also increased
D) Consistent only if protoporphyrin can be demonstrated using Ehrlich reagent

Question 26

The silver nitroprusside test detects the presence of:

A) Propionic acid
B) Homocystine
C) Uroporphyrin
D) Cystine

Question 27

The most common cause of acquired porphyria is:

A) Alcoholism
B) Lead poisoning
C) Iron-deficiency anemia
D) Liver failure

Question 28

To differentiate between cystinuria and homocystinuria,the urine should be tested with:

A) Cyanide nitroprusside
B) Ferric chloride
C) Clinitest
D) Silver nitroprusside

Question 29

A false-positive test for 5-HIAA may result if the patient:

A) Does not collect a complete 24-hour urine
B) Does not receive appropriate diet instructions
C) Fails to fast prior to specimen collection
D) Stores the specimen in the refrigerator overnight

Question 30

The specimen of choice when testing for protoporphyrin is:

A) Blood
B) Urine
C) Bile
D) Feces

Question 31

The finding of increased amounts of the serotonin degradation product 5-HIAA in the urine indicates:

A) Platelet disorders
B) Intestinal obstruction
C) Malabsorption syndromes
D) Argentaffin cell tumors

Question 32

Patients who produce kidney stones at an early age should be tested for the presence of:

A) Organic acidemia
B) Cystinuria
C) Maple syrup urine disease
D) PKU

Question 33

Symptoms of inherited porphyrias include all of the following except:

A) Fanconi syndrome
B) Neurologic
C) Psychiatric
D) Photosensitivity

Question 34

Analysis of urine from an infant whose mother reported a blue staining on the diapers showed increased levels of indican and a generalized aminoaciduria.On the basis of these findings,the infant was diagnosed as having:

A) An intestinal obstruction
B) A protein malabsorption syndrome
C) Fanconi syndrome
D) Hartnup disease

Question 35

The presence of porphobilinogen in the urine can be suspected when:

A) Acidic urine turns a port wine color after standing
B) Alkaline urine turns a port wine color after standing
C) Freshly excreted urine is acidic and port wine in color
D) Freshly excreted urine is alkaline and port wine in color

Question 36

Porphyrins are intermediary compounds in the formation of:

A) Amino acids
B) Serotonin
C) Heme
D) Bilirubin

Question 37

A pink color in the Hoesch test indicates the presence of:

A) Urobilinogen
B) Myoglobin
C) Porphobilinogen
D) Nitrite

Question 38

Abnormal amounts of indigo blue in the urine are indicative of a defect in the metabolism of:

A) Phenylalanine
B) Tyrosine
C) Tryptophan
D) Cystine

Question 39

The finding of a "blue diaper" is indicative of a defect in the metabolism of:

A) Phenylalanine
B) Tyrosine
C) Tryptophan
D) Cystine

Question 40

Which of the following compounds does not react directly with either Ehrlich reagent or fluorescence?

A) Uroporphyrin
B) Aminolevulinic acid
C) Coproporphyrin
D) Porphobilinogen

Question 41

Mental retardation is a symptom of all of the following except:

A) Hurler's syndrome
B) Galactosuria
C) PKU
D) Cystinuria

Question 42

All of the following can be classified as metabolic rather than renal disorders except:

A) Tyrosyluria
B) Maple syrup urine disease
C) Cystinuria
D) Indicanuria

Question 43

Choose cystinuria or cystinosis as the best match for the following statements of the condition:
Generalized aminoaciduria

A) Cystinuria
B) Cystinosis

Question 44

A specimen that produces a cherry red color with Ehrlich's reagent is extracted into chloroform,and both the aqueous and chloroform layers are red.You should:

A) Repeat the test with chloroform from a new bottle
B) Extract the aqueous layer into more chloroform
C) Extract the specimen into butanol
D) Report the presence of both urobilinogen and porphobilinogen

Question 45

The acid albumin CTAB test is used to test for:

A) Carbohydrates
B) Fecal fats
C) Mucopolysaccharides
D) Maple syrup urine disease

Question 46

The appearance of abnormal metabolites in the urine due to a defect categorized as an "overflow type" may be caused by all of the following except:

A) Inborn errors of metabolism
B) Serum concentrations exceeding the Tm
C) Abnormalities in the tubular reabsorption mechanism
D) Disruption of normal enzyme function by exposure to toxic substances

Question 47

Choose cystinuria or cystinosis as the best match for the following statements of the condition:
Defective reabsorption of cystine,lysine,ornithine,and arginine

A) Cystinuria
B) Cystinosis

Question 48

The presence of "orange sand" in an infant's diaper is indicative of:

A) Cystinuria
B) Bilirubinuria
C) Maple syrup urine disease
D) Lesch-Nyhan disease

Question 49

Characteristic urine odors are associated with all of the following disorders except:

A) Alkaptonuria
B) PKU
C) Maple syrup urine disease
D) Isovaleric acidemia

Question 50

Melituria refers to an increase in urinary:

A) Melanin
B) Uric acid
C) Cholesterol
D) Sugar

Question 51

Choose cystinuria or cystinosis as the best match for the following statements of the condition:
Fanconi syndrome

A) Cystinuria
B) Cystinosis

Question 52

Select the appropriate screening test result for the following disorders:
PKU

A) Ferric chloride
B) Clinitest
C) Acetest
D) Nitroso-naphthol

Question 53

Select the appropriate screening test result for the following disorders:
Tyrosyluria

A) Nitroso-naphthol
B) Acetest
C) Silver nitroprusside
D) p-nitroaniline

Question 54

A patient diagnosed with Lesch-Nyhan disease can have all of the following conditions,except:

A) Cystinosis
B) Increase in uric acid
C) Self-destructive tendencies
D) Severe motor defects

Question 55

The concept of vampires is associated with:

A) Cystinosis
B) Hunter syndrome
C) Sanfilippo syndrome
D) Porphyrias

Question 56

Choose cystinuria or cystinosis as the best match for the following statements of the condition:
Tendency to form renal calculi

A) Cystinuria
B) Cystinosis

Question 57

Hurler and Sanfilippo syndromes present with mental retardation and an increase in what urinary constituent:

A) Porphyrins
B) Amino acids
C) Maltose
D) Mucopolysaccharides

Question 58

GALT deficiency is a disorder affecting the metabolism of:

A) Glucose
B) Fructose
C) Lactose
D) Galactose

Question 59

The presence of amino acids is of particular concern in which population?

A) Pregnant women
B) Newborns
C) Adolescent males
D) Menopausal women

Question 60

Choose cystinuria or cystinosis as the best match for the following statements of the condition:
True inborn of metabolism

A) Cystinuria
B) Cystinosis

Question 61

Choose the characteristic odor for the following disorders:
Cystinosis

A) Sulfur
B) Sweet
C) Sweaty feet
D) Mousy

Question 62

The following urinalysis results are obtained from a newborn:

Based on the information provided,what additional unusual characteristic might be found in this urine?

A) Uric acid crystals
B) Renal tubular epithelial cells
C) Odor
D) Positive Clinitest

Question 63

State what action the urinalysis supervisor could take in the following situations:
A new employee consistently obtains negative Watson-Schwartz test results on suspected cases of lead poisoning.

A) Check the Ehrlich reagent
B) Confirm addition of acetylacetone
C) Confirm the specimen has been centrifuged
D) Check the employee for color-blindness

Question 64

The following urinalysis results are obtained from a newborn:

Based on the information provided,what screening test should be performed on this specimen?

A) p-nitroaniline
B) DNPH
C) Nitroso-naphthol
D) Both B and C

Question 65

Both cystine and leucine crystals are present in the urine of patients with cystinuria.

Question 66

Select the appropriate screening test result for the following disorders:
Homocystinuria

A) Cyanide-nitroprusside
B) Acetest
C) Silver nitroprusside
D) Ehrlich reaction

Question 67

Argentaffin cell tumors produce large amounts of serotonin.

Question 68

State what action the urinalysis supervisor could take in the following situations:
An employee reports a negative nitroso-napthol test on a suspected case of tyrosyluria.

A) Perform an Ehrlich test
B) Collect a blood sample for MS/MS testing
C) Request a new urine specimen
D) Perform an Acetest

Question 69

Select the appropriate screening test result for the following disorders:
Methylmalonic acidemia

A) Ferric chloride
B) p-Nitroaniline
C) Cyanide-nitroprusside
D) Clinitest

Question 70

Persons diagnosed with PKU should avoid foods containing the chemical additive aspartame.

Question 71

State what action the urinalysis supervisor could take in the following situations:
Many uric acid crystals are reported in the urine of a 15-year-old boy with an unremarkable medical history,except for previous episodes of renal calculi.

A) Check for possible cystine crystals
B) Check for specimen mix-up
C) Notify the health-care provider
D) Report possible Lesch-Nyhan disease

Question 72

Choose the characteristic odor for the following disorders:
Phenylketonuria

A) Sweet
B) Sulfur
C) Mousy
D) Sweaty feet

Question 73

The following urinalysis results are obtained from a newborn:

Based on the information provided,what is the infant's most probable disorder?

A) Lesch-Nyhan disease
B) Isovaleric acidemia
C) Maple syrup urine disease
D) Tyrosyluria

Question 74

Choose the characteristic odor for the following disorders:
Isovaleric acidemia

A) Mousy
B) Sweaty feet
C) Sulfur
D) Aromatic

Question 75

Select the appropriate screening test result for the following disorders:
Hurler syndrome

A) Ferric chloride
B) Clinitest
C) Nitroso-naphthol
D) CTAB test

Question 76

Failure of a metabolic pathway to reach completion may be caused by an inborn error of metabolism.

Question 77

State what action the urinalysis supervisor could take in the following situations:
A positive Clinitest with a yellow precipitate is noted from a patient with liver and cardiac abnormalities.

A) Repeat the Clinitest with new reagents
B) Check for parenteral feeding
C) Check the patient's urine for color change
D) Draw blood for plasma glucose

Question 78

Choose the characteristic odor for the following disorders:
Maple syrup urine disease

A) Mousy
B) Ammonia
C) Sulfur
D) Sweet

Question 79

State what action the urinalysis supervisor could take in the following situations:
An employee questions the finding of a positive glucose on a yellow-blue urine from an underweight child with a normal blood glucose.

A) Request a new specimen
B) Perform a Clinitest
C) Check for possible Hartnup disease diagnosis
D) Check for possible juvenile diabetes mellitus

Question 80

The 2,4-dinitrophenylhydrazine reaction is the confirmatory test for maple syrup urine disease.