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Trimethylaminuria (TMA) with Creatinine Testing, Urine

Test ID: TMACRE U

Test

Aliases/Synonyms

Trimethylamine; Trimethylamine N-Oxide

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 %
  • ≥ 92
TMA/TMAO Profile
  • Normal

Test Version

11-Nov-2025

Interface / Setup

Test Version

11-Nov-2025