Alberta Precision Laboratories

--- Query Results ---

Organization:

Alberta Precision Laboratories

Message Alert:

PLEASE NOTE: This Test Directory is in an interim state and due to changes pertaining to the DynaLIFE transition, performing site for routing has not been updated. Please refer to Laboratory Information System for appropriate routing.

Test Name/Synonym:

3-Methylglutaconic and 3-Methylglutaric Acids, Urine (Synonyms: MGA, 3MGC, 3MGA, MGCA)

Clinical Indications:

Primary 3MGC Disorders Detectable by elevated 3-methylglutaconic and 3-methylglutaric acids:

3-methylglutaconyl-CoA hydratase deficiency (3MGC type I; AUH)
3-hydroxy-3-methylglutaryl-CoA lyase deficiency

Secondary 3MGC Disorders Detectable by elevated 3-methylglutaconic and 3-methylglutaric acids:

Barth syndrome (3MGC type II; TAZ)
Costeff Optic Atrophy syndrome (3MGC type III; OPA3)
MEGDEL syndrome (3MGC type IV; SERAC1)
Dilated Cardiomyopathy with Ataxia syndrome (3MGC type V; DNAJC19)
TMEM70 defect (TMEM70)

Other known causes of elevated 3-methylglutaconic and 3-methylglutaric acids:

CLPB (caseinolytic peptidase B) deficiency
Carbamoyl phosphate synthetase I deficiency and other urea cycle disorders
Some mitochondrial diseases
Some neuromuscular diseases
Some glycogen storage disorders
Primary carnitine deficiency
Other metabolic disorders (due to secondary mitochondrial dysfunction)

Test Includes:

3-methylglutaconic acid, 3-methylglutaric acid

Ordering Alert:

This test is considered specialty testing; this test will be cancelled if sufficient clinical justification is not provided.

Urine 3-methylglutaconic and 3-methylglutaric acids should not be ordered in conjunction with urine organic acids, as these metabolites are also reported as part of that test, and this quantitative test will be reflexively performed on any urine sample with elevated levels detected, sample volume permitting.

LABID (Connect Care):

LAB4001

Test Code:

CALGARY ZONE	BGLNON; IN BGL TEST NAME FIELD ENTER 3-METHYLGLUTA
SOUTH ZONE (LETHBRIDGE)	MISC
SOUTH ZONE (MEDICINE HAT)	3METHYLUR, 3MGA
OTHER ZONES	NOT SPECIFIED

Specimen Type:

Urine

Primary Container:

Sterile Urine Container

Minimum Collection Volume:

1.0 mL

Specimen Collection Requirements:

Collect a 5.0 to 10.0 mL random urine specimen.

Test Resources:

Submit request using the applicable requisition or Connect Care online order entry:

Biochemical Genetics Laboratory Requisition

Please ensure all required information, including patient's clinical history/indication, is provided on the requisition.

Stability and Storage:

Frozen

Processing:

This test requires creatinine determination for result reporting. For sites using EPIC, a separate aliquot should be removed at the time of initial specimen receipt and sent to the EPIC-designated lab for creatinine testing.

One aliquot with primary container, or two separate aliquots, can be submitted. Write “urine” on all secondary aliquot tubes. Freeze container and/or tubes.

Transportation:

Transport frozen specimens on dry ice.
Samples must not thaw during transport.

Method:

Gas chromatography-mass spectrometry (GC-MS)

Method and Interpretation of Results:

3-Methylglutaconic and 3-methylglutaric acids are 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.

Urine 3-methylglutaconic and 3-methylglutaric acids can help to inform whether elevated plasma levels are due to a true 3-methylglutaconic aciduria or renal insufficiency, both of which can lead to a mild to moderate elevations of plasma 3-methylglutaconic and 3-methylglutaric acids.

This test will be reflexively performed when elevated 3-methylglutaconic and/or 3-methylglutaric acids are found by Organic Acids, Semi-Quantitative.

Routine Turn Around Time:

30 days

Testing Schedule:

Monthly

Reference Interval:

Metabolite	Age	mmol/mol Cr
3-methylglutaconic acid	less than 45 months	3.5 to 20.0
	45-160 months	1.7 to 9.1
	greater than 160 months	1.0 to 6.8
3-methylglutaric acid	less than 45 months	0.3 to 2.0
	45-160 months	0.2 to 1.6
	greater than 160 months	0.1 to 1.6

Performing Site:

Alberta Children's Hospital

Additional Test Information:

For priority turn-around contact Biochemical Genetics South Laboratory.

Contact Comments:

Biochemical Genetics 403-955-7379

Last Updated On:

Monday, October 24, 2022

Date of Last Review:

Aug 1 2022 12:00AM