Trimethylamine; Trimethylamine N-Oxide
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Trimethylaminuria (TMA) with Creatinine Testing, Urine
Test ID: TMACRE U
Test
Aliases/Synonyms
Method
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
Report Includes
TMA/TMAO Profile; TMAO (%)
Specimens
Urine
Test Version
11-Nov-2025
Specimen
Specimens
Urine
Collection Containers
Sterile Container
Sample Volume
5.0 mL
Minimum Volume
1.0 mL
Patient Preparation
- Very dilute urines cannot be accurately tested.
- Menstruating patients should avoid collection of urines during, or within a few days of, their period.
- This laboratory recommends two urine specimens (pre- and post-choline load), but one post-choline load is sufficient. If two samples are sent, both samples will be billed for.
Pre-choline load specimen is collected when the patient is eating an unrestricted diet and odor is present.
Post-choline load specimen should be collected about 12 hours after the patient has ingested choline bitartrate with a glass of orange juice or water [5 gm (5000 mg) of choline bitartrate for patients > 12 years and weighing more than 54 kg (120 lbs); 2.5 gm (2500 mg) for patients aged > 12 years and weighing 54 kg (120 lbs) or less.]. Ingestion of a choline load may cause stomach upset in some patients and is not recommended for patients age < 12 years. A heavy meal of choline-rich foods may be substituted for the ingestion of choline bitartrate in patients age <12 years.
Collection & Handling
Collection Instructions
This laboratory recommends two urine specimens (pre- and post-choline load), but one post-choline load is sufficient. If two samples are sent, both samples will be billed for. Both the pre-choline and post-choline specimens should be shipped together.
Clearly label each of the specimens “pre” and “post“.
Handling Information
Freeze immediately after each collection. Store and send frozen.
Stability
| Frozen | 180 days |
|---|
Additional Stability Information
Frozen @ -80 Celsius: Indefinitely
Test Version
11-Nov-2025
Performance / Interpretation
Method
Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)
Turnaround Time
25 days
Results
| Name | Units | Reference Range | Conversion Factor | |
|---|---|---|---|---|
| TMAO Percent, Urine | % |
|
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| TMA/TMAO Profile |
|
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Test Version
11-Nov-2025
Interface / Setup
Test Version
11-Nov-2025