CRDPU - Overview: Creatine Disorders Panel, Urine

Test Catalog

Test Name

Test ID: CRDPU    
Creatine Disorders Panel, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluation of patients with a clinical suspicion of inborn errors of creatine metabolism including arginine:glycine amidinotransferase deficiency, guanidinoacetate methyltransferase deficiency, and creatine transporter (SLC6A8) defect

Genetics Test Information Provides information that may help with selection of the correct genetic test or proper submission of the test request



Depletion of cerebral creatine occurs in all 3 types of creatine deficiency syndromes (CDS): arginine:glycine amidinotransferase (AGAT) deficiency, guanidinoacetate methyltransferase (GAMT) deficiency, and creatine transporter (SLC6A8) deficiency.


Measurement of guanidinoacetate (GAA), creatine (Cr), and creatinine (Crn) in urine along with the Cr:Crn ratio  distinguishes among the types of creatine deficiency syndromes.


Treatment with oral creatine supplementation is effective in some types of CDS.


Creatine supplementation may cause increased creatine values.

Additional Tests Lists tests that are always performed, at an additional charge, with the initial tests

Test IDReporting NameAvailable SeparatelyAlways Performed
CRBOCreatine, (Bill Only), UNoYes
CRNBOCreatinine, (Bill Only), UNoYes
GAABOGuanidinoacetate, (Bill Only), UNoYes

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

CRDPU / Creatine Disorders Panel, Urine is a single test that carries the results for the panel. When the test is resulted, the following procedures are billed:

-23466 / Creatine, Urine (Bill Only)

-23467 / Creatinine, Urine (Bill Only)

-23468 / Guanidinoacetate, Urine (Bill Only)


See Newborn Screen Follow-up for Guanidinoacetate Methyltransferase Deficiency (GAMT) in Special Instructions.


For more information, see Newborn Screening Act Sheet Guanidinoacetate Methyltransferase Deficiency: Increased Guanidinoacetate in Special Instructions.

Special Instructions and Forms Library of PDFs including pertinent information and consent forms, specimen collection and preparation information, test algorithms, and other information pertinent to test

Method Name A short description of the method used to perform the test

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

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name A shorter or abbreviated version of the Published Name for a test; an abbreviated test name

Creatine Disorders Panel, U

Aliases Lists additional common names for a test, as an aid in searching

AGAT (Arginine:Glycine Amidinotransferase) Deficiency
Arginine:Glycine Amidinotransferase Deficiency (AGAT)
CrT1 defect
GAMT (Guanidinoacetate Methyltransferase) Deficiency
Guanidinoacetate Methyltransferase (GAMT) Deficiency