Chapter 7 - Urine Screening for Metabolic Disorders Flashcards

1
Q

2 categories of aminoaciduria

A

Overflow or renal

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2
Q

Type of aminoaciduria with increased amino acid in blood and urine

A

Overflow type

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3
Q

Type of aminoaciduria with increased amino acid in urine but normal in blood

A

Renal type

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4
Q

Identify whether the ff are overflow or renal type aminoaciduria:

  1. MSUD
  2. Cystinuria
  3. PKU
  4. Fanconi’s syndrome
A
  1. Overflow
  2. Renal
  3. Overflow
  4. Renal
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5
Q

Failure to inherit a gene that codes for a particular enzyme

A

Inborn error of metabolism (IEM)

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6
Q

Testing for many substances is now performed using _____. It is capable of screening the infant blood sample for specific substances assoc w/ particular IEMs.

A

Tandem mass spectrophotometry (MS/MS)

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7
Q

Matching type:

  1. MSUD
  2. PKU
  3. Argentaffinoma
  4. Melanuria
  5. Tyrosyluria/Tyrosinemia
  6. Indicanuria
  7. Alkaptonuria
  8. Organic acidemias
  9. Cystinosis
  10. Hunter syndrome
  11. Lesch-Nyhan syndrome
  12. Sanfilippo syndrome
  13. Fructosuria
  14. Galactosuria
  15. Cystinuria
  16. Homocystinuria
  17. Hurler syndrome
A. Phenylalanine-tyrosine disorders
B. Cystine disorders
C. Carbohydrate disorders
D. Porphyrin disorders 
E. Purine disorders
F. Mucopolysaccharide disorders
G. Branched-chain amino acid disorders
H. Tryptophan disorders
A
  1. G
  2. A
  3. H
  4. A
  5. A
  6. H
  7. A
  8. G
  9. B
  10. F
  11. E
  12. E
  13. C
  14. C
  15. B
  16. B
  17. F
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8
Q

Most well known of the aminoacidurias

A

PKU

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9
Q

In PKU, the gene that codes for the production of the enzyme _____, is absent.

A

Phenylalanine hydroxylase

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10
Q

Guthrie test is an obsolete screening test for which metabolic disorder?

A

PKU

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11
Q

Positive FeCl3 tube test for the ff:

  1. PKU
  2. Tyrosinemia
  3. Alkaptonuria
  4. Melanuria
  5. Argentaffinoma
A
  1. Blue-green
  2. Transient green
  3. Transient blue
  4. Gray/black precipitate
  5. Blue-green
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12
Q

Screening tests for PKU

A

FeCl3 tube test, phenistix strip, Guthrie bacterial inhibition test

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13
Q

Confimatory test for PKU

A

Ion exchange HPLC

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14
Q

Bacteria used in Guthrie test

A

B. subtilis

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15
Q

Regarding Guthrie test, the positive test for px w/ PKU is?

A

Bacterial growth

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16
Q

Regarding Guthrie test, what inhibits the growth of B. subtilis?

A

B2-thienylalanine

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17
Q

Regarding Guthrie test, what inhibits B2-thienylalanine?

A

Phenylalanine

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18
Q

Positive result of phenistix strip for px w/ PKU

A

Gray to gray-green

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19
Q

What type of tyrosyluria/tyrosinemia are described?

  1. Gene that codes for p-hydroxyphenylpyruvic acid dioxygenase is absent
  2. Gene that codes for tyrosine aminotransferase is absent
  3. Gene that codes for fumarylacetoacetate hydrolase
A
  1. Type 3
  2. Type 2
  3. Type 1
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20
Q

Screening tests for tyrosinemia

A

FeCl3 tube test, nitroso-naphthol

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21
Q

Confirmatory test for tyrosinemia

A

Chromatography, quantitative serum assay of tyrosine

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22
Q

Positive result for nitroso-naphthol for px w/ tyrosyluria/tyrosinemia

A

Orange-red

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23
Q

For px w/ alkpatonuria, the gene that codes for ____, is absent

A

Homogentisic acid

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24
Q

Urine darkens upon air exposure

A

Melanuria

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25
Q

Urine darkens after becoming alkaline from standing at room temp

A

Alkaptonuria

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26
Q

Screening tests for alkaptonuria

A

FeCl3 tube test, clinitest

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27
Q

Confirmatory tests for alkaptonuria

A

Paper/thin layer chromatography, capillary electrophoresis

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28
Q

Reddish-stained disposable diapers

A

Alkaptonuria

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29
Q

Brown- or black-stained cloth diapers

A

Alkaptonuria

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30
Q

Caused by melanoma, tumor involving melanocytes

A

Melanuria

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31
Q

Regarding melanuria, tumors secrete _____, which oxidizes to melanogen then to melanin

A

5,6-dihydroxyindole

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32
Q

Screening tests for melanuria

A

FeCl3 tube test, sodium nitroprusside test, Ehrlich test

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33
Q

Positive result of clinitest for alkaptonuria

A

Yellow precipitate

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34
Q

Positive result for sodium nitroprusside test for melanuria

A

Red

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35
Q

Positive result for Ehrlich test for melanuria

A

Red

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36
Q

Most common IEM in the Philippines

A

MSUD

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37
Q

For px w/ MSUD, the gene that codes for the enzyme for metabolism of the ketoacids of _____, _____, and _____.

A

Leucine, isoleucine, valine

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38
Q

Screening test for MSUD

A

2,4-dinitrophenylhydrazine (DNPH)

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39
Q

Confirmatory test for MSUD

A

Gas or thin-layer chromatography, nuclear magnetic resonance spectro

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40
Q

Glutaric acidemia aka

A

Isovaleric acidemia

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41
Q

Organic acidemia detected using p-nitroaniline test

A

Methylmalonic acidemia

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42
Q

p-nitroaniline test positive result for methylmalonic acidemia

A

Emerald green

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43
Q

For px w/ indicanuria, their urine color turns into ____ upon air exposure

A

Indigo blue

44
Q

Blue-diaper syndrome

A

Hartnup’s disease

45
Q

Indicanuria is seen in which conditions?

A

Hartnup’s disease & intestinal disorders

46
Q

What bacteria can also make urine color blue?

A

P. aeruginosa

47
Q

Phenyalalanine hydroxylase converts phenylalanine to ____.

A

Tyrosine

48
Q

Screening test for indicanuria

A

Obermayer’s test

49
Q

Obermayer’s test for indicanuria rgts

A

FeCl3, chloroform

50
Q

Positive result for Obermayer’s test for indicanuria

A

Violet

51
Q

Tyrosine aminotransferase converts tyrosine to:

A

p-hydroxyphenylpyruvic acid

52
Q

p-hydroxyphenylpyruvate pxidase converts p-hydroxyphenylpyruvic acid into?

A

Homogentisic acid

53
Q

Homogentisic acid oxidase converts homogentisic acid into?

A

Maleylacetoacetic acid

54
Q

Maleylacetoacetic acid isomerase converts maleylacetoacetic acid into?

A

Fumarylacetoacetic acid

55
Q

Fumarylacetoacetic acid hydrolase converts fumarylacetoacetic acid into?

A

Fumaric acid & acetoacetic acid

56
Q

Increased in type 1a tyrosinemia

A

Fumarylacetoacetic acid

57
Q

Increased in type 1b tyrosinemia

A

Maleylacetoacetic acid

58
Q

Increased in type 2 tyrosinemia

A

Tyrosine

59
Q

Increased in type 3 tyrosinemia

A

p-hydroxyphenylpyruvic acid

60
Q

Normal degradation product of tryptophan

A

Indole

61
Q

What converts tryptophan to excess indole?

A

Bacteria

62
Q

What organ converts excess indole to indican?

A

Liver

63
Q

Indole is usually found in?

A

Feces

64
Q

Argentaffinoma is a tumor of _____ cells.

A

Argentaffin/enterochromaffin

65
Q

Enterochromaffin/argentaffin cells produce _____

A

Serotonin

66
Q

Serotonin metabolic product

A

5-HIAA

67
Q

Screening tests for argentaffinoma

A

FeCl3 tube test, nitroso-naphthol w/ nitrous acid

68
Q

Positive result for Nitrosonaphthol w/ nitrous acid for argentaffinoma

A

Violet

69
Q

Px w/ argentaffinoma should avoid eating _____.

A

Bananas, tomatoes, pineapples

70
Q

Tests for cystinuria and cystinosis

A

Brand’s modification of Legal’s nitroprusside, thin layer or ion-exchange chromatography, high-voltage electrophoresis

71
Q

During cystinuria, defective tubular reabsorption of which amino acids are present?

A

Cystine, ornithine, lysine, arginine

72
Q

Reagent for Brand’s modofication of Legal’s nitroprusside

A

Cyanide nitroprusside

73
Q

Positive color for Brand’s modification of Legal’s nitroprusside

A

Red-purple

74
Q

Which of the following is an inborn error of metabolism?

A. Cystinuria
B. Cystinosis

A

B. Cystinosis

75
Q

Gene that codes for enzyme responsible for cystine metabolism is not present

A. Cystinuria
B. Cystinosis
C. Homocystinuria

A

B. Cystinosis

76
Q

Defects in the metabolism of methionine leading to increased homocystine

A

Homocystinuria

77
Q

During homocystinuria, the gene that codes for the enzyme _____ is absent.

A

Cystathione B-synthase

78
Q

Homocystinuria is detected by the _____ test with a positive result of _____.

A

Silver-nitroprusside; red-purple

79
Q

Urine color for px w/ porphyrin disorders

A

Red, purple, burgundy-red, purplish red, portwine

80
Q

Color of urine in lead poisoning

A

Colorless

81
Q

Match the ff porphyrin disorders with the corresponding enzymes that are absent:

  1. ALA hydratase deficiency porphyria
  2. Acute intermittent porphyria
  3. Hereditary coproporphyria
  4. Variegate porphyria
  5. Congenital erythropoietic porphyria
  6. Porphyria cutanea tarda
A. Protoporphyrinogen
B. Uroporphyrinogen synthase
C. Uroporphyrinogen cosynthase
D. Coproporphyrinogen oxidase
E. Uroporphyrinogen decarboxylase
F. Aminolevulinic acid synthetase
A
  1. F
  2. B
  3. D
  4. A
  5. C
  6. E
82
Q

Screening test specimens for porphyrias

A

Urine, stool, blood, bile

83
Q

Which enzymes are affected during lead poisoning?

A

ALA synthetase

Ferrochelatase

84
Q

Upon lead exposure, which heme precursors may be increased?

A

D-ALA & protoporphyrin IX

85
Q

Ehrlich’s rxn for porphyrias detects:

A

D-ALA & porphobilinogen

86
Q

CDC recommended test for lead poisoning

A

Free erythrocyte protoporphyrin (FEP)

87
Q

Fluorescence at 550-600 nm tests for which heme precursors?

A

Uroporphyrin, coproporphyrin & protoporphyrin

88
Q

Positive result for fluorescence at 550-600 nm for porphyrias

A

Violet / pink / red fluorescence

89
Q

Metabolic disorder where dermatan sulfate, keratan sulfate and heparan sulfate are frenquently found in the px urine

A

Mucopolysaccharide disorders

90
Q

Screening tests for mucopolysaccharide disorders

A

Acid albumin, cetyltrimethylammoniumbromide (CTAB) test, mucopolysaccharide paper test

91
Q

What are the positive results for each of the ff MPS disorder screening tests?

  1. Acid albumin
  2. CTAB test
  3. MPS paper test
A
  1. White turbidity
  2. White turbidity
  3. Blue color
92
Q

Which MPS disorder is described:

  1. Sex-linked recessive, rarely seen in females, skeletal abnormalities, and mental retardation present
  2. Mental retardation is the only abnormality
  3. MPS accumulate in the cornea of the eye, skeletal abnormalities & mental retardation present
A
  1. Hunter syndrome
  2. Sanfilippo syndrome
  3. Hurler syndrome
93
Q

Metab disorder wherein the gene that codes for the enzyme hypoxanthine guanine phosphoribosyltransferase is absent

A

Lesch-Nyhan disease

94
Q

Purine disorder

A

Lesch-Nyhan syndrome

95
Q

During Lesch-Nyhan syndrome, uric acid is increased in the blood and urine causing ______ in diapers

A

Orange sand

96
Q

Presence of any sugar in urine

A

Melituria

97
Q

During carbohydrate disorders, what is the expected result in rgt strip and in copper reduction test?

A

Rgt strip - Negative

Copper reduction - Positive

98
Q

Most severe carbohydrate disorder because it is assoc with infant failure to thrive, liver disorders, cataracts and severe mental retardation

A

Galactosemia/galactosuria

99
Q

Inability to metabolize galactose to glucose

A

Galactosemia/galactosuria

100
Q

Match the ff benign carb disorders w/ their descriptions:

  1. Assoc with ingestion of large amt of fruit
  2. Seen during pregnancy & lactation
  3. Assoc with parental feeding

A. Lactosuria
B. Pentosuria
C. Fructosuria

A
  1. B. Pentosuria
  2. A. Lactosuria
  3. C. Fructosuria
101
Q

Newborn screening: State laws require that blood be collected after _____ after birth and before newborn leaves the hospital

A

24 hrs

102
Q

Deficient production of melanin results in?

A

Albinism

103
Q

True or false: the appearance of black urine from a px OF ANY AGE should be reported to the supervisor

A

True

104
Q

A significant lab finding in branched-chain amino acid disorders is the presence of ____ in a newborn

A

Ketonuria

105
Q

The sweaty feet odor in isovalericc acidemia is caused by the accumulation of _____

A

Isovalerylglycine

106
Q

The portwine urine color is more prevalent in the ____ porphyrias

A

Erythropoietic

107
Q

Lead poisoning inhibits _____ and _____ enzymes

A

ALA synthetase, ferrochelatase