Urine Screening for Metabolic Disorders Flashcards
Two types of aminoaciduria
Overflow type
Renal type
Increase Amino acid in blood
Increase Amino acid in urine
Ex. PKU, MSUD
Overflow type
Normal Amino acid in blood
Increase Amino acid in urine
*defect in tubular reabsorption
Ex. Cystinuria, Fanconi’s syndrome
Renal type
- for identifying metabolism disorder.
- for early detection and treatment
Newborn Screening Tests RA #______
9288
Newborn Screening Tests is done after
24 hrs of life
Newborn Screening Tests: massage the _____ of the baby for _______ and prick on the ______.
Heel
3 minutes
Side of the heel
well known aminoacidurias
(-) gene that codes for Phenylalanine hydroxylase
Phenylketonuria
Phenylketonuria clinical manifestations: (2)
• Mousy urine odor
• May lead to severe mental retardation
Phenylketonuria screening tests results:
• FeCl3 tube test:
• Phenistix strip:
• Guthrie bacterial inhibition test:
*B. subtilis is cultured with _______
• FeCl3 tube test: (+) blue-green color
• Phenistix strip: (+) gray to gray-green
• Guthrie bacterial inhibition test: (+) growth
*B. subtilis is cultured with β-2-thienylalanine
Confirmatory test for phenylketonuria
Ion exchange HPLC (High Performance Liquid Chromatography)
Tyrosyluria/Tyrosinemia Clinical manifestations:
• Rancid butter urine odor
• Tyrosine and Leucine crystals in urine (SEVERE LIVER DISEASE)
Tyrosyluria/Tyrosinemia
(-) gene that codes for:
Type 1:
Type 2:
Type 3:
Type 1: Fumarylacetoacetate hydrolase (FAH)
Type 2: Tyrosine aminotransferase
Type 3: p-hydroxyphenylpyruvic acid dioxygenase
Tyrosyluria/Tyrosinemia screening tests result:
FeCl3 tube test:
Nitroso-naphthol:
FeCl3 tube test: (+) transient green
Nitroso-naphthol: (+) orange-red
Tyrosyluria/Tyrosinemia Confirmatory tests: Confirmatory tests (2)
Chromatography
Quantitative serum assay of tyrosine
(-) gene that codes for Homogentisic acid oxidase
Urine darkens after becoming alkaline from standing at room temperature
• Brown or black stained cloth diapers • Reddish stained disposable diapers
ALKAPTONURIA
ALKAPTONURIA Clinical manifestations:
Dark blue to black pigmentation of cartilage and connective tissues & liver
ALKAPTONURIA screening test result:
• FeCl3 tube test:
• Clinitest:
_______ of fresh urine
• FeCl3 tube test: (+) transient blue
• Clinitest: (+) yellow precipitate
Alkalinization of fresh urine
Confirmatory Tests for alkaptonuria
• Paper/thin-layer chromatography
• Capillary electrophoresis
Caused by melanoma (tumor involving melanocytes)
Tumors secrete _________, which oxidizes to melanogen then to melanin
Urine darkens upon ________
Melanuria
5,6-dihydroxyindole
air exposure
Clinical manifestations of melanuria
Malignant melanoma
Melanuria screening test result:
FeCl3 tube test:
Sodium nitroprusside test:
Ehrlich test=
FeCl3 tube test: (+) gray/black ppt
Sodium nitroprusside test: (+) red
Ehrlich test= (+) Red
-most common inborn error of metabolism in the PH
(-) Gene that codes for enzyme for metabolism of the ketoacids of Leucine, Isoleucine and Valine
Maple Syrup Urine Disease (MSUD)
Clinical manifestations of Maple Syrup Urine Disease (MSUD):
• Caramelized sugar/Maple syrup/Curry urine odor
• Failure to thrive, mental retardation
Screening test for Maple Syrup Urine Disease (MSUD) result:
2,4-dinitrophenylhydrazine (DNPH):
2,4-dinitrophenylhydrazine (DNPH): (+) yellow turbidity/ppt
Confirmatory Test for Maple Syrup Urine Disease (MSUD): (2)
Gas/Thin layer chromatography
Nuclear magnetic resonance spectro.
What are the Organic Acidemias: (3)
a. Isovaleric acidemia: Sweaty feet urine odor
b. Propionic acidemia
c. Methylmalonic acidemia: detected using p-nitroaniline test : (+) emerald green color
Indigo color of urine upon air exposure
Indicanuria
Indicanuria is seen in? (2)
Intestinal disorders (increase level of tryptophan)
Hartnup disease= Blue diaper syndrome
Screening test for Indicanuria result: Obermayer’s
FeCl3 + Urine + Chloroform=
(+) violet color
Increase level of 5-HIAA (Hydroxyl Indole Acetic Acid) in urine (increase
serotonin)
Carcinoid tumor involving argentaffin/enterochromaffin cells/ Kulchitsky’s cells
Argentaffinoma
Screening test result for Argentaffinoma:
FeCl3 tube test:
Nitrosonaphthol w/ nitrous acid:
FeCl3 tube test: (+) Blue-green
Nitrosonaphthol w/ nitrous acid: (+) Violet
For individuals with Argentaffinoma, Avoid eating (6)
bananas
pineapples
tomatoes
chocolate
walnuts
plums
Renal type of amino aciduria
Defective tubular reabsorption
Cystinuria
Cystinuria
Renal type of amino aciduria
Defective tubular reabsorption (4)
• Cystine
• Ornithine
• Lysine
• Arginine
Tests for cystinuria: (3)
TEST:
• Brand’s modification of Legal’s nitroprusside
Reagent: Cyanide Nitroprusside (+) Red-purple color
• Thin layer or Ion exchange chromatography
• High-voltage electrophoresis
What disorder has sulfur in urine
Cystinuria
Inborn error of metabolism Overflow type
(-) gene that codes for an enzyme responsible for cystine metabolism
Cystine deposits in many areas of the body (BM, cornea, lymph nodes and internal organs)
Cystinosis
Test for Cystinosis and result
• Brand’s modification of Legal’s nitroprusside
Reagent: Cyanide Nitroprusside (+) Red-purple color
Defects in the metabolism of methionine (leads to increase homocystine)
(-) gene that codes for the enzyme cystathionine β-synthase
Homocystinuria
Test result for Homocystinuria:
Silver-nitroprusside test: (+) Red-purple color
(+) Red-purple color
Porphyrin Disorders (Porphyrias)
Disorders of porphyrin metabolism
Urine color:
Colorless in:
Porphyrin Disorders (Porphyrias)
Disorders of porphyrin metabolism
Urine color: Red/Purple/Burgundy-Red/Purplish-Red/Portwine
Colorless in: Lead poisoning
ALA hydratase deficiency porphyria: (-) Gene that codes for
Aminolevulinic acid (ALA) synthetase
Acute intermittent porphyria: (-) Gene that codes for
Uroporphyrinogen synthase
Congenital erythropoietic porphyria: (-) Gene that codes for
Uroporphyrinogen cosynthase
Porphyria cutanea tarda: (-) Gene that codes for
Uroporphyrinogen decarboxylase
Hereditary coproporphyria: (-) Gene that codes for
Coproporphyrinogen oxidase
Variegate porphyria: (-) Gene that codes for
Protoporphyrinogen oxidase
SCREENING TESTS for Porphyrin Disorders (Porphyrias):
Ehrlich’s reaction=
Fluorescence at 550-600 nm=
Free erythrocyte protoporphyrin (FEP)=
Ehrlich’s reaction= Detects D-ALA, porphobilinogen
Fluorescence at 550-600 nm= Tests for uroporphyrin, coproporphyrin & protoporphyrin
(+) Violet/Pink/Red fluorescence
Free erythrocyte protoporphyrin (FEP)= CDC-recommended test for lead poisoning
Impaired metabolism of mucopolysaccharides or glycosaminoglycans (protein +polysaccharides, located in the connective tissues)
Mucopolysaccharide (MPS) Disorders
(Mucopolysaccharidosis)
Mucopolysaccharide (MPS) Disorders
(Mucopolysaccharidosis): Frequently found in urine are (3)
= dermatan sulfate
= keratan sulfate
= heparan sulfate
MPS accumulate in the cornea of the eye
Skeletal abnormality & mental retardation present
MPS accumulate in the cornea of the eye
Skeletal abnormality & mental retardation present
Sex-linked recessive, rarely seen in females Skeletal abnormality & mental retardation present
Hunter syndrome
Mental retardation is the only abnormality
Sanfilippo syndrome
SCREENING TEST FOR MPS (3)
Acid albumin
Cetyltrimethylammoniumbromide (CTAB) test
Mucopolysaccharide (MPS) Paper Test
SCREENING TEST FOR MPS results:
- Acid albumin=
- Cetyltrimethylammoniumbromide (CTAB) test=
- Mucopolysaccharide (MPS) Paper Test=
- Acid albumin= (+)white turbidity
- Cetyltrimethylammoniumbromide (CTAB) test= (+) white turbidity
- Mucopolysaccharide (MPS) Paper Test (+) Blue color
(-) gene that codes for the enzyme hypoxanthine guanine phosphoribosyltransferase
Increase uric acid in the blood and urine= “orange sand in diapers”, gout
Lesch-Nyhan Disease
Inability to metabolize galactose to glucose
Associated with infant failure to thrive, liver disorders, cataracts and severe mental retardation
Galactosemia/Galactosuria
seen during pregnancy and lactation
Lactosuria
associated with parenteral feeding
Fructosuria
associated with ingestion of large amounts of fruit
Pentosuria
