Cobalamin, Methionine, and Methylmalonic Acid Pathways, Plasma
Use
This test is useful for screening and monitoring patients suspected of or confirmed with an inherited disorder of methionine, cobalamin, or propionate metabolism using plasma specimens. It is also used for evaluating individuals with a suspected deficiency of vitamin B12. These conditions can lead to medical issues such as enzyme deficiencies in propionate metabolism, homocystinuria, and conditions related to vitamin B12 deficiency. By assessing levels of metabolites such as homocysteine, methylmalonic acid (MMA), and methylcitric acid among others, the test assists in diagnosing and managing these metabolic disorders.
Special Instructions
Patient's age and sex are required for the test. Specimen collection requires immediate cooling on ice and processing (centrifugation and plasma separation into a plastic vial) within specific time frames. Utilize the correct collection tubes and follow instructions for sample stability.
Limitations
The test is subject to limitations based on the proper collection and handling of plasma specimens. Gross hemolysis, lipemia, and icterus are accepted but could potentially affect results if extreme. Proper patient preparation and specimen handling are critical to avoid invalid results.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.4 mL
Container
Plastic vial
Collection Instructions
Immediately place specimen on ice. Within 4 hours of collection, centrifuge and aliquot plasma into plastic vial. If blood cannot be placed on wet ice immediately, centrifuge and aliquot plasma into a plastic vial within 1 hour of collection. A refrigerated centrifuge is not required if the above time restrictions are met.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 28 days |
| Refrigerated | 28 days |
| Frozen | 309 days |