Urine organic acid (Qualitative)
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Synonyms
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Why do we do this test?
Diagnosis of inborn errors of metabolism especially when organic aciduria is suspected
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Specimen Type
Urine (spot/ timed collection) |
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Instructions for specimen
collection & Patient preparation
Urine ideally is collected at the time of acute illness. If patient is asymptomatic a random urine sample is appropriate.
Collect to a clean container without preservatives
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Specimen transportation &
Processing
Specimen preferably transported frozen
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Specimen storage & stability
Freeze as soon as possible at -20 °C
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Specimen storage duration
Stable at -20° C or lower for several years
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Reference Intervals & Target
Values
Since this is a qualitative test an interpretive report will be provided
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Critical Limits
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Possible Pre-analytical Errors
Diet (including TPN, gelatin, medium-chain triglyceride oil supplements, infant formula, ketogenic diet)
Medications (valproate, levetiracetam, aspirin, benzoic acid, ibuprofen, acetaminophen )
Bacterial contamination due to improper handling of samples
Informative profiles may not always be detected in disorders where the excretion of diagnostic metabolites is a reflection of the residual activity of the defective enzyme, the dietary load of precursors, and the anabolic/catabolic status of a patient.
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Possible Analytical Errors
Analyte co-elution
Contaminants
Extraction efficiency
Incomplete derivatization
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Available Government Laboratories
Lady Ridgeway Hospital for Children, Department of Chemical Pathology
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Recommended turnaround time
Minimum 1 week
(If the analysis is urgent contact the Department of Chemical Pathology, LRH with clinician recommendation)
Maximum 3 months
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Test Method
Gas Chromatography Mass Spectrometry
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Documentation
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References
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Last Updated : 2020-09-14 04:43:32 |