Expected Turnaround Time
4 - 10 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Information
Related Documents
Specimen Requirements
Specimen
Cerebrospinal fluid (CSF), frozen
Volume
0.5 mL
Minimum Volume
0.15 mL (Note: This volume does not allow for repeat testing.)
Container
Plastic transport tube
Collection
To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Storage Instructions
Freeze.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | Unstable |
Refrigerated | Unstable |
Frozen | 14 days |
Causes for Rejection
Gross contamination with blood; room temperature or thawed specimen
Test Details
Use
Diagnosis and monitoring of inherited aminoacidurias. Most notably, quantitation of amino acids in CSF is useful in the diagnosis of glycine encephalopathy. CSF samples are most informative when a plasma sample is collected at the same time and ratios of the amino acid concentrations in CSF to plasma are calculated.
Limitations
False-negative results can occur, especially when a patient is affected with a mild or intermittent variant of a disorder, or when clinical condition or dietary treatment causes secondary changes to the profile. Results of amino acid profiling should be interpreted in the context of clinical presentation as well as other laboratory tests.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Reference Interval
See Cerebrospinal Fluid Amino Acid Reference Intervals in the Test Resources pages online.
References
Bremer HJ, Duran M, Kamerling JP, et al. Disturbances of Amino Acid Metabolism: Clinical Chemistry and Diagnosis. Baltimore, Md: Urban and Schwarzenberg; 1981.
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 700180 | Amino Acid Profile, Qn, CSF | 700141 | Taurine | umol/L | 26614-8 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700142 | Aspartate | umol/L | 22655-5 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700143 | Threonine | umol/L | 22643-1 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700144 | Serine | umol/L | 22644-9 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700145 | Asparagine | umol/L | 26603-1 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700146 | Glutamate | umol/L | 22652-2 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700147 | Glutamine | umol/L | 22641-5 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700148 | Glycine | umol/L | 22650-6 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700149 | Alanine | umol/L | 22657-1 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700150 | Citrulline | umol/L | 22654-8 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700151 | Valine | umol/L | 22649-8 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700152 | Cystine | umol/L | 22653-0 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700153 | Methionine | umol/L | 22648-0 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700154 | Isoleucine | umol/L | 22659-7 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700155 | Leucine | umol/L | 9412-8 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700156 | Tyrosine | umol/L | 22642-3 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700157 | Phenylalanine | umol/L | 22646-4 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700158 | Beta-alanine | umol/L | 26589-2 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700159 | Gamma-aminobutyrate | umol/L | 26594-2 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700160 | Ornithine | umol/L | 22647-2 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700161 | Lysine | umol/L | 22651-4 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700162 | Histidine | umol/L | 9453-2 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700163 | Arginine | umol/L | 22656-3 | |
| 700180 | Amino Acid Profile, Qn, CSF | 700164 | Interpretation | 49303-1 | ||
| 700180 | Amino Acid Profile, Qn, CSF | 700165 | Director Review | 72486-4 | ||
| 700180 | Amino Acid Profile, Qn, CSF | 700166 | Methodology | 49549-9 | ||
| 700180 | Amino Acid Profile, Qn, CSF | 700471 | Disclaimer: | N/A |
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