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Test Code LAB1136 Creatine Disorders Panel, Random, Urine

Additional Codes

Mayo Test ID
CRDPU

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Evaluating patients with a clinical suspicion of arginine:glycine amidinotransferase deficiency, guanidinoacetate methyltransferase deficiency, and creatine transporter (SLC6A8) defect

Testing Algorithm

This is a single test that carries the results for the panel. When the test has been resulted, the following procedures are billed:

-CRBO / Creatine, Urine (Bill Only)

-CRNBO / Creatinine, Urine (Bill Only)

-GAABO / Guanidinoacetate, Urine (Bill Only)

 

For more information see:

-Newborn Screen Follow-up for Guanidinoacetate Methyltransferase Deficiency (GAMT)

-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm

Method Name

Liquid Chromatography Tandem Mass Spectometry (LC-MS/MS)

Reporting Name

Creatine Disorders Panel, U

Specimen Type

Urine


Necessary Information


Patient's age and sex are required.



Specimen Required


Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10 mL urine tube

Specimen Volume: 1 mL

Collection Instructions:

1. Collect a random urine specimen.

2. Immediately freeze urine specimen.

3. If possible, do not send other tests ordered on same vial of urine. In doing so, the other tests may have increased turnaround time due to the strict frozen criteria of this assay.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen 29 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

Males

Age

Creatinine (nmol/mL)

Guanidinoacetate (nmol/mL)

Creatine (nmol/mL)

Creatine/

creatinine

≤31 days

430-5,240

9-210

12-2,930

0.02-0.93

32 days-23 months

313-9,040

16-860

18-10,490

0.02-2.49

2-4 years

1,140-12,820

90-1,260

200-9,210

0.04-1.75

5-18 years

1,190-25,270

40-1,190

60-9,530

0.01-0.96

>18 years (male)

3,854-23,340

30-710

7-470

0.00-0.04

 

Females

Age

Creatinine (nmol/mL)

Guanidinoacetate (nmol/mL)

Creatine (nmol/mL)

Creatine/

creatinine

≤31 days

430-5,240

9-210

12-2,930

0.02-0.93

32 days-23 months

313-9,040

16-860

18-10,490

0.02-2.49

2-4 years

1,140-12,820

90-1,260

200-9,210

0.04-1.75

5-18 years

1,190-25,270

40-1,190

60-9,530

0.01-0.96

>18 years

1,540-18,050

30-760

5-2810

0.00-0.46

Interpretation

Reports include concentrations of guanidinoacetate, creatine, and creatinine, as well as a calculated creatine:creatinine ratio. When no significant abnormalities are detected, a simple descriptive interpretation is provided. When abnormal results are detected, a detailed interpretation is given. This interpretation includes an overview of the results and their significance, a correlation to available clinical information, elements of differential diagnosis, and recommendations for additional biochemical testing.

Day(s) Performed

Tuesday

Report Available

3 to 9 days

Specimen Retention Time

1 month

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

82540

82570

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CRDPU Creatine Disorders Panel, U 79290-3

 

Result ID Test Result Name Result LOINC Value
23383 Creatine 15046-6
23384 Creatinine 14683-7
23385 Guanidinoacetate 97148-1
23268 Creatine/Creatinine Ratio 34275-8
23270 Creatine Disorders Panel Interp 79292-9
23272 Reviewed By 18771-6

Additional Tests

Test ID Reporting Name Available Separately Always Performed
CRBO Creatine, (Bill Only), U No Yes
CRNBO Creatinine, (Bill Only), U No Yes
GAABO Guanidinoacetate, (Bill Only), U No Yes