--- Query Results ---

  
Program:Genetics and Genomics
 
Test Name:Methylmalonic Acid (G&G South ACH)
Test Code:MMA-P, MMA-S, MMA-U
Performing Site: Alberta Children's Hospital
Performing Dept:Biochemical Genetics
 
Availability:Test performed on a weekly basis.
TAT:14 days
 
Preferred Tube/Container:Sodium heparin (dark green - NOT PST)
Alternate:
Lithium heparin (dark green - NOT PST)
Non-additive (red top - NOT SST)
Random specimen: plain urine container
 
Specimen Requirements:For Blood Samples:
1.  Collect 1 x 4.0 mL sodium heparin tube (or alternate tube type).
2.  Collect following a minimum four-hour fast; or just before next feed for newborns.
3.  Indicate length of fast, or time of last feeding on the requisition (with collection time).

For Urine Samples:
Collect a 5 to 10 mL random urine sample.
 
Min. Sample Required:0.5 mL plasma or serum or 1.0 mL urine
 
Specimen Processing:For Blood Samples:
At ACH only
The primary heparinized tube can be put on ice (ensure not to freeze sample) or refrigerated for routine pick-ups between 8:30 am – 2:30 pm, Monday through Friday.

For all other collections
1. Centrifuge.
2. Transfer plasma or serum to aliquot tube.
3. Write "NaHep", "LiHep" or "Red Top" on the aliquot tube label.
4. Freeze.

For Urine Samples:
1.  If specimen is transferred to secondary aliquot tube or container, write "urine" on label.
2.  Freeze.
 
Specimen Handling:Transport frozen samples on ice. Samples must not thaw during transport.
 
Additional Information:Samples will be rejected if:
  • Primary blood tube not refrigerated
  • Primary urine container not refrigerated or frozen
  • Aliquot tube received thawed
  • Tube type not written on aliquot tube label
  •  
    Requisition/Form:Submit request using Biochemical Genetics Laboratory Requisition.
    Please ensure all required information, including patient's clinical history/indication, is provided on the requisition.
     
    Order Restrictions:This test is considered specialty testing; this test will be cancelled if sufficient clinical justification is not provided.

    Plasma methylmalonic acid test should only be ordered when there is a high index of clinical suspicion of a nutritional B12 deficiency, based on patient presentation.
    Urine methylmalonic acid test should not be ordered in conjunction with urine organic acids, as this metabolite is also reported as part of that test, and this test will be reflexively performed on any urine sample with elevated levels detected.
     
    Indications:Plasma methylmalonic acid can aid in the diagnosis of functional B12 deficiency when the plasma B12 levels are in the low-normal range (150 to 400 pmol/L).
    Urine methylmalonic acid can aid in differentiating between a true functional B12 deficiency and renal insufficiency, both of which can lead to a mild to moderate elevation of plasma methylmalonic acid.
    Method:Methylmalonic acid is detected following derivatization (i.e., silylation) using a gas chromatography-mass spectrometry (GC-MS) stable isotope dilution (SID) method with a deuterium-labeled internal standard.
    Method Details:Methylmalonic acid can be elevated in the following enzyme deficiencies / disorders:
  • methylmalonyl-CoA mutase deficiency
  • methylmalonyl-CoA epimerase deficiency
  • cobalamin (Cbl) A, B, C, D, F, J and X deficiencies
  • intrinsic factor deficiency and Imerslund-Grasbeck syndrome
  • transcobalamin II deficiency
  • ACSF3 deficiency (a.k.a., combined malonic and methylmalonic aciduria or CMAMMA)
  • SUCLA2 and SUCLG1 deficiencies

    Other causes of elevated methylmalonic acid:
  • nutritional vitamin B12 deficiency
  • renal insufficiency (plasma/serum only)
  •  
    Reference Interval:
    Plasma/serum Methylmalonic Acid          (0-18 years)  0.04 – 0.20  µmol/l
    Plasma/serum Methylmalonic Acid        (18-60 years)  0.05 – 0.27  µmol/l
    Plasma/serum Methylmalonic Acid           (>60 years)  0.06 – 0.36  µmol/l
    Urine Methylmalonic Acid          0 -<5.0  mmol/mol creatinine
     
    Comments:Contact ACH Biochemical Genetics Laboratory (403-955-7379) for priority turn-around.
     
     
    Last Updated On:Tuesday, May 22, 2018
    Date of Last Review:Jan 2 2018 12:00AM