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Test Code TRYPU Tryptophan, Random, Urine

Reporting Name

Tryptophan, U

Useful For

Aiding in the screening and monitoring of Hartnup disease

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Ordering Guidance


Other body fluids are not acceptable specimens for this test. For testing spinal fluid specimens, order AACSF / Amino Acids, Quantitative, Spinal Fluid.

 

Testing for tryptophan using plasma specimens is available; order TRYPP / Tryptophan, Plasma.



Necessary Information


1. Patient's age is required.

2. Include family history, clinical condition (asymptomatic or acute episode), diet, and drug therapy information.



Specimen Required


Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 2 mL

Collection Instructions: Collect a random urine specimen.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen (preferred) 70 days
  Refrigerated  14 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

<2 months: <241 nmol/mg creatinine

2-35 months: <329 nmol/mg creatinine

3-6 years: <222 nmol/mg creatinine

7-17 years: <218 nmol/mg creatinine

≥18 years: <140 nmol/mg creatinine

Day(s) Performed

Monday through Friday

CPT Code Information

82131

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TRYPU Tryptophan, U 28608-8

 

Result ID Test Result Name Result LOINC Value
83823 Tryptophan, U 28608-8
34618 Interpretation (TRYPU) 59462-2
113131 Reviewed By 18771-6

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

Report Available

3 to 5 days

NY State Approved

Yes