Test Catalog

Test Id : CRDPP

Creatine Disorders Panel, Plasma

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

Evaluation of patients with a clinical suspicion of arginine:glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency.

 

This test is not useful for the diagnosis of creatine transporter deficiency.

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 deficiency, guanidinoacetate methyltransferase deficiency, and creatine transporter deficiency.

 

Measurement of guanidinoacetate, creatine, and creatinine along with associated analyte ratios in plasma and urine distinguishes among the types of creatine deficiency syndromes.

 

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

 

Creatine supplementation may impact reliability of test results.

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

Special Instructions
Library of PDFs including pertinent information and forms related to the test

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

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

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

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Creatine Disorders Panel, P

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

AGAT (Arginine:Glycine Amidinotransferase) Deficiency

Arginine:Glycine Amidinotransferase Deficiency (AGAT)

Creatine disorders

Creatine plasma

Creatine/creatinine ratio plasma

Creatinine plasma

GAMT (Guanidinoacetate Methyltransferase) Deficiency

Guanidinoacetate

Guanidinoacetate Methyltransferase (GAMT) Deficiency

Guanidinoacetic acid (GAA)

L-Arginine:Glycine Amidinotransferase Deficiency (AGAT)

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

Specimen Type
Describes the specimen type validated for testing

Plasma

Ordering Guidance

For diagnosis of creatine transporter deficiency, order CRDPU / Creatine Disorders Panel, Random, Urine.

Additional Testing Requirements

To diagnose all creatine deficiency syndromes, order CRDPU / Creatine Disorders Panel, Random, Urine in addition to this test.

Necessary Information

Patient's age and sex are required.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Green top (sodium heparin), yellow top (ACD)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot plasma into plastic vial. Send plasma frozen.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Plasma Frozen (preferred) 14 days
Refrigerated 7 days
Ambient 72 hours

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

Evaluation of patients with a clinical suspicion of arginine:glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency.

 

This test is not useful for the diagnosis of creatine transporter deficiency.

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 deficiency, guanidinoacetate methyltransferase deficiency, and creatine transporter deficiency.

 

Measurement of guanidinoacetate, creatine, and creatinine along with associated analyte ratios in plasma and urine distinguishes among the types of creatine deficiency syndromes.

 

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

 

Creatine supplementation may impact reliability of test results.

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

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Disorders of creatine synthesis (guanidinoacetate methyltransferase: GAMT, L-arginine:glycine amidinotransferases: AGAT, and creatine transporter deficiency: CTD) are collectively described as creatine deficiency syndromes (CDS). GAMT and AGAT deficiencies are inherited in an autosomal recessive manner, while CTD is X-linked. All 3 disorders result in a depletion of cerebral creatine and typically present with global developmental delays, intellectual disability, and severe speech delay. Affected patients may have abnormal magnetic resonance imaging findings and exhibit cerebral creatine deficiency in brain magnetic resonance spectroscopy. Patients with GAMT and male patients with CTD develop seizures, behavioral problems, and autistic features and may have abnormal movements. Female carriers for CTD can be asymptomatic or exhibit features similar to affected male patients such as intellectual disability, behavioral problems, and seizures.

 

Diagnosis of creatine synthesis disorders relies on measurement of guanidinoacetate (GAA), creatine (Cr), and creatinine (Crn) in serum and urine. The profiles are specific for each clinical entity. In serum, patients with GAMT deficiency typically exhibit very elevated GAA, low Cr, and normal to low Crn. Patients with AGAT deficiency typically exhibit low to normal GAA, low Cr, and normal to low Crn. In comparison, patients with CTD typically have normal serum levels of GAA, Cr and Crn, and measurement of these analytes in urine is required for diagnosis in male patients (characteristic findings are elevated Cr, normal to low Crn, and an elevated Cr:Crn ratio in urine). The only reliable method for diagnosis of CTD in female patients is molecular analysis of the SLC6A8 gene. The diagnosis of GAMT and AGAT can be confirmed by molecular analysis of GAMT and GATM.

 

Treatment with oral supplementation of creatine monohydrate is available and effective for the AGAT and GAMT deficiencies. Patients with GAMT deficiency may also be treated with supplemental ornithine and dietary arginine restriction.

 

Early treatment has been reported to prevent disease manifestations in affected but presymptomatic newborn siblings of individuals with GAMT or AGAT deficiencies.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Creatine Disorders Panel Reference Values
(creatine, creatinine, and guanidinoacetate results reported as nmol/mL)

 

< or =11 Months

12-23 Months

24-35 Months

Female

Male

Female

Male

Female

Male

Creatine

38.6-96.8

39.0-97.0

38.2-96.5

38.6-96.5

37.7-96.0

38.2-96.0

Creatinine

27.6-35.9

27.6-35.2

27.6-36.5

27.6-35.5

27.6-37.1

27.6-36.0

Guanidinoacetate

0.7-2.0

0.7-2.1

0.7-2.0

0.7-2.1

0.7-2.0

0.7-2.1

Creatine/
creatinine

< or =3.07

< or =3.60

< or =3.02

< or =3.54

< or =2.96

< or =3.48

Guanidinoacetate/
creatine

< or =0.040

< or =0.040

< or =0.042

< or =0.040

< or =0.043

< or =0.042

Guanidinoacetate/
creatinine

< or =0.051

< or =0.081

< or =0.051

< or =0.080

< or =0.051

< or =0.079

 

 

3 Years

4 Years

5 Years

Female

Male

Female

Male

Female

Male

Creatine

37.1-95.5

37.7-95.3

36.0-94.4

36.8-94.1

34.6-93.2

35.6-92.7

Creatinine

27.6-37.9

27.7-36.9

27.6-39.3

27.7-38.2

27.6-40.9

27.8-39.9

Guanidinoacetate

0.7-2.1

0.7-2.2

0.7-2.1

0.7-2.2

0.7-2.1

0.7-2.2

Creatine/
creatinine

< or =2.89

< or =3.40

< or =2.77

< or =3.26

< or =2.64

< or =3.09

Guanidinoacetate/
creatine

< or =0.045

< or =0.043

< or =0.049

< or =0.045

< or =0.053

< or =0.049

Guanidinoacetate/
creatinine

< or =0.050

< or =0.077

< or =0.050

< or =0.075

< or =0.049

< or =0.072

 

 

6 Years

7 Years

8 Years

Female

Male

Female

Male

Female

Male

Creatine

33.0-91.7

34.3-91.0

31.2-90.0

32.7-89.2

29.2-88.1

31.0-87.3

Creatinine

27.6-42.8

28.0-41.9

27.7-44.9

28.3-44.3

27.8-47.0

28.8-47.1

Guanidinoacetate

0.7-2.1

0.7-2.3

0.7-2.1

0.8-2.3

0.8-2.1

0.8-2.4

Creatine/
creatinine

< or =2.49

< or =2.91

< or =2.33

< or =2.70

< or =2.17

< or =2.49

Guanidinoacetate/
creatine

< or =0.058

< or =0.053

< or =0.063

< or =0.058

< or =0.069

< or =0.064

Guanidinoacetate/
creatinine

< or =0.049

< or =0.069

< or =0.048

< or =0.066

< or =0.047

< or =0.063

 

 

9 Years

10 Years

11 Years

Female

Male

Female

Male

Female

Male

Creatine

27.2-85.9

29.3-85.2

25.2-83.7

27.4-83.1

23.4-81.3

25.7-80.9

Creatinine

28.0-49.3

29.5-50.1

28.2-51.5

30.6-53.6

28.4-53.6

32.0-57.2

Guanidinoacetate

0.8-2.2

0.8-2.5

0.9-2.2

0.9-2.6

0.9-2.2

1.0-2.6

Creatine/
creatinine

< or =2.02

< or =2.28

< or =1.86

< or =2.07

< or =1.72

< or =1.87

Guanidinoacetate/
creatine

< or =0.075

< or =0.070

< or =0.081

< or =0.078

< or =0.087

< or =0.085

Guanidinoacetate/
creatinine

< or =0.047

< or =0.060

< or =0.046

< or =0.057

< or =0.045

< or =0.055

 

 

12 Years

13 Years

14 Years

Female

Male

Female

Male

Female

Male

Creatine

21.7-78.7

23.9-78.6

20.3-76.2

22.3-76.2

19.0-73.6

20.8-73.8

Creatinine

28.7-55.7

33.8-61.0

29.1-57.7

35.9-64.8

29.5-59.5

38.1-68.5

Guanidinoacetate

0.9-2.2

1.0-2.7

1.0-2.3

1.1-2.8

1.0-2.3

1.1-2.9

Creatine/
creatinine

< or =1.58

< or =1.68

< or =1.45

< or =1.50

< or =1.33

< or =1.34

Guanidinoacetate/
creatine

< or =0.092

< or =0.093

< or =0.097

< or =0.101

< or =0.101

< or =0.109

Guanidinoacetate/
creatinine

< or =0.044

< or =0.053

< or =0.043

< or =0.051

< or =0.042

< or =0.050

 

 

15 Years

16 Years

17 Years

Female

Male

Female

Male

Female

Male

Creatine

18.1-71.1

19.5-71.2

17.4-68.7

18.4-68.6

16.9-66.5

17.4-65.9

Creatinine

29.9-61.3

40.4-71.9

30.4-62.9

42.4-75.0

30.9-64.4

44.2-77.6

Guanidinoacetate

1.0-2.3

1.2-2.9

1.1-2.3

1.3-3.0

1.1-2.3

1.3-3.1

Creatine/
creatinine

< or =1.22

< or =1.20

< or =1.12

< or =1.07

< or =1.04

< or =0.97

Guanidinoacetate/
creatine

< or =0.104

< or =0.117

< or =0.107

< or =0.125

< or =0.109

< or =0.132

Guanidinoacetate/
creatinine

< or =0.041

< or =0.049

< or =0.040

< or =0.048

< or =0.040

< or =0.048

 

 

18 Years

19 Years

20 Years

Female

Male

Female

Male

Female

Male

Creatine

16.7-64.4

16.6-63.3

16.6-62.7

15.8-60.7

16.5-61.1

15.2-58.3

Creatinine

31.3-65.8

45.6-80.0

31.8-67.0

46.7-82.0

32.2-68.2

47.4-83.9

Guanidinoacetate

1.1-2.4

1.4-3.1

1.1-2.4

1.4-3.2

1.1-2.4

1.5-3.2

Creatine/
creatinine

< or =0.98

< or =0.87

< or =0.93

< or =0.80

< or =0.89

< or =0.73

Guanidinoacetate/
creatine

< or =0.111

< or =0.139

< or =0.112

< or =0.145

< or =0.113

< or =0.150

Guanidinoacetate/
creatinine

< or =0.039

< or =0.047

< or =0.038

< or =0.047

< or =0.038

< or =0.046

 

 

21 Years

22 Years

23 Years

Female

Male

Female

Male

Female

Male

Creatine

16.6-59.8

14.7-56.0

16.6-58.8

14.2-54.0

16.7-57.9

13.7-52.2

Creatinine

32.5-69.2

47.9-85.6

 32.8-70.2

48.2-87.2

 33.1-71.1

48.4-88.8

Guanidinoacetate

1.1-2.4

1.5-3.2

1.1-2.5

1.5-3.3

1.1-2.5

1.6-3.3

Creatine/
creatinine

< or =0.87

< or =0.68

< or =0.85

< or =0.64

< or =0.84

< or =0.61

Guanidinoacetate/
creatine

< or =0.114

< or =0.156

< or =0.115

< or =0.161

< or =0.116

< or =0.165

Guanidinoacetate/
creatinine

< or =0.037

< or =0.045

< or =0.037

< or =0.045

< or =0.037

< or =0.044

 

 

24 Years

25 Years

26 Years

Female

Male

Female

Male

Female

Male

Creatine

16.7-57.2

13.3-50.6

16.7-56.5

12.9-49.3

16.7-56.0

12.5-48.1

Creatinine

33.3-71.9

48.6-90.2

33.6-72.8

48.7-91.5

33.7-73.6

48.9-92.7

Guanidinoacetate

1.1-2.5

1.6-3.3

1.1-2.5

1.6-3.3

1.1-2.6

1.6-3.4

Creatine/
creatinine

< or =0.84

< or =0.58

< or =0.84

< or =0.56

< or =0.84

< or =0.54

Guanidinoacetate/
creatine

< or =0.116

< or =0.170

< or =0.117

< or =0.174

< or =0.118

< or =0.179

Guanidinoacetate/
creatinine

< or =0.036

< or =0.043

< or =0.036

< or =0.043

< or =0.036

< or =0.042

 

 

27 Years

28 Years

29 Years

Female

Male

Female

Male

Female

Male

Creatine

16.7-55.5

12.1-47.1

16.6-55.1

11.8-46.3

16.5-54.7

11.5-45.4

Creatinine

33.9-74.4

49.0-93.7

34.1-75.2

49.1-94.5

34.2-76.0

49.2-95.3

Guanidinoacetate

1.1-2.6

1.6-3.4

1.1-2.6

1.6-3.4

1.1-2.6

1.6-3.4

Creatine/
creatinine

< or =0.84

< or =0.52

< or =0.84

< or =0.51

< or =0.84

< or =0.49

Guanidinoacetate/
creatine

< or =0.118

< or =0.182

< or =0.119

< or =0.186

< or =0.119

< or =0.188

Guanidinoacetate/
creatinine

< or =0.036

< or =0.042

< or =0.036

< or =0.041

< or =0.036

< or =0.041

 

 

30 Years

31 Years

32 Years

Female

Male

Female

Male

Female

Male

Creatine

16.4-54.2

11.3-44.7

16.4-53.8

11.1-43.9

16.3-53.4

11.0-43.2

Creatinine

34.4-76.8

49.3-96.0

34.6-77.5

49.3-96.7

34.7-78.2

49.4-97.4

Guanidinoacetate

1.2-2.7

1.6-3.5

1.2-2.7

1.6-3.5

1.2-2.7

1.6-3.5

Creatine/
creatinine

< or =0.84

< or =0.48

< or =0.83

< or =0.47

< or =0.83

< or =0.46

Guanidinoacetate/
creatine

< or =0.120

< or =0.190

< or =0.120

< or =0.192

< or =0.119

< or =0.192

Guanidinoacetate/
creatinine

< or =0.036

< or =0.041

< or =0.036

< or =0.042

< or =0.037

< or =0.042

 

 

33 Years

34 Years

35 Years

Female

Male

Female

Male

Female

Male

Creatine

16.3-53.0

10.9-42.5

16.4-52.7

10.8-41.7

16.4-52.3

10.7-41.0

Creatinine

34.9-78.8

49.4-98.0

35.1-79.4

49.5-98.6

35.3-79.9

49.5-99.2

Guanidinoacetate

1.2-2.8

1.6-3.5

1.2-2.8

1.6-3.5

1.2-2.8

1.6-3.4

Creatine/
creatinine

< or =0.82

< or =0.45

< or =0.82

< or =0.45

< or =0.82

< or =0.44

Guanidinoacetate/
creatine

< or =0.119

< or =0.192

< or =0.118

< or =0.191

< or =0.118

< or =0.189

Guanidinoacetate/
creatinine

< or =0.037

< or =0.042

< or =0.037

< or =0.042

< or =0.037

< or =0.042

 

 

36 Years

37 Years

38 Years

Female

Male

Female

Male

Female

Male

Creatine

16.5-52.0

10.7-40.2

16.7-51.6

10.6-39.5

16.9-51.3

10.6-38.9

Creatinine

35.4-80.3

49.5-99.8

35.6-80.7

49.5-100.3

35.8-81.0

49.6-100.8

Guanidinoacetate

1.2-2.8

1.6-3.4

1.2-2.8

1.6-3.4

1.2-2.9

1.6-3.4

Creatine/
creatinine

< or =0.82

< or =0.44

< or =0.82

< or =0.44

< or =0.83

< or =0.44

Guanidinoacetate/
creatine

< or =0.117

< or =0.187

< or =0.115

< or =0.184

< or =0.114

< or =0.182

Guanidinoacetate/
creatinine

< or =0.037

< or =0.042

< or =0.037

< or =0.042

< or =0.036

< or =0.042

 

 

39 Years

40 Years

41 Years

Female

Male

Female

Male

Female

Male

Creatine

17.1-51.1

10.6-38.2

17.3-50.9

10.7-37.7

17.5-50.8

10.7-37.2

Creatinine

35.9-81.4

49.6-101.3

36.0-81.6

49.6-101.7

36.1-81.9

49.7-102.1

Guanidinoacetate

1.2-2.9

1.6-3.4

1.2-2.9

1.6-3.4

1.2-2.9

1.6-3.4

Creatine/
creatinine

< or =0.83

< or =0.44

< or =0.83

< or =0.44

< or =0.84

< or =0.44

Guanidinoacetate/
creatine

< or =0.113

< or =0.179

< or =0.111

< or =0.176

< or =0.110

< or =0.174

Guanidinoacetate/
creatinine

< or =0.036

< or =0.041

< or =0.036

< or =0.041

< or =0.036

< or =0.040

 

 

42 Years

43 Years

44 Years

Female

Male

Female

Male

Female

Male

Creatine

17.7-50.8

10.8-36.7

17.8-50.8

10.9-36.3

17.8-50.9

11.0-36.0

Creatinine

36.2-82.1

49.7-102.5

36.3-82.4

49.8-102.8

36.4-82.6

49.8-103.1

Guanidinoacetate

1.2-3.0

1.6-3.3

1.2-3.0

1.6-3.3

1.2-3.0

1.6-3.3

Creatine/
creatinine

< or =0.84

< or =0.44

< or =0.84

< or =0.43

< or =0.84

< or =0.43

Guanidinoacetate/
creatine

< or =0.109

< or =0.172

< or =0.108

< or =0.171

< or =0.107

< or =0.170

Guanidinoacetate/
creatinine

< or =0.036

< or =0.039

< or =0.036

< or =0.039

< or =0.036

< or =0.038

 

 

45 Years

46 Years

47 Years

Female

Male

Female

Male

Female

Male

Creatine

17.7-51.0

11.1-35.6

17.6-51.2

11.2-35.3

17.4-51.4

11.3-35.1

Creatinine

36.4-82.8

49.9-103.4

36.5-83.0

49.9-103.6

36.5-83.2

49.9-103.9

Guanidinoacetate

1.2-3.0

1.7-3.3

1.2-3.1

1.7-3.3

1.2-3.1

1.7-3.3

Creatine/
creatinine

< or =0.84

< or =0.42

< or =0.83

< or =0.41

< or =0.83

< or =0.40

Guanidinoacetate/
creatine

< or =0.106

< or =0.169

< or =0.106

< or =0.168

< or =0.106

< or =0.167

Guanidinoacetate/
creatinine

< or =0.037

< or =0.038

< or =0.037

< or =0.037

< or =0.037

< or =0.037

 

 

48 Years

49 Years

50 Years

Female

Male

Female

Male

Female

Male

Creatine

17.2-51.7

11.5-34.8

17.1-51.9

11.6-34.6

17.0-52.1

11.7-34.4

Creatinine

36.6-83.4

49.9-104.1

36.6-83.5

49.9-104.2

36.7-83.7

49.9-104.4

Guanidinoacetate

1.2-3.1

1.7-3.3

1.2-3.1

1.7-3.3

1.2-3.1

1.7-3.3

Creatine/
creatinine

< or =0.82

< or =0.39

< or =0.82

< or =0.38

< or =0.82

< or =0.38

Guanidinoacetate/
creatine

< or =0.106

< or =0.166

< or =0.106

< or =0.164

< or =0.105

< or =0.163

Guanidinoacetate/
creatinine

< or =0.038

< or =0.036

< or =0.038

< or =0.036

< or =0.039

< or =0.036

 

 

51 Years

52 Years

53 Years

Female

Male

Female

Male

Female

Male

Creatine

17.0-52.2

11.9-34.3

17.1-52.3

12.0-34.3

17.3-52.4

12.2-34.3

Creatinine

36.8-83.9

49.8-104.6

36.8-84.0

49.8-104.8

36.9-84.2

49.8-104.9

Guanidinoacetate

1.2-3.1

1.7-3.3

1.2-3.1

1.7-3.2

1.2-3.1

1.6-3.2

Creatine/
creatinine

< or =0.82

< or =0.37

< or =0.82

< or =0.37

< or =0.82

< or =0.38

Guanidinoacetate/
creatine

< or =0.105

< or =0.161

< or =0.104

< or =0.159

< or =0.103

< or =0.157

Guanidinoacetate/
creatinine

< or =0.039

< or =0.036

< or =0.039

< or =0.036

< or =0.039

< or =0.036

 

 

54 Years

55 Years

56 Years

Female

Male

Female

Male

Female

Male

Creatine

17.6-52.5

12.4-34.3

18.1-52.6

12.5-34.4

18.6-52.7

12.6-34.4

Creatinine

37.0-84.4

49.8-105.0

37.1-84.5

49.8-105.2

37.2-84.7

49.8-105.3

Guanidinoacetate

1.2-3.1

1.6-3.2

1.2-3.1

1.6-3.2

1.2-3.1

1.6-3.2

Creatine/
creatinine

< or =0.82

< or =0.38

< or =0.83

< or =0.39

< or =0.84

< or =0.40

Guanidinoacetate/
creatine

< or =0.102

< or =0.155

< or =0.100

< or =0.154

< or =0.099

< or =0.152

Guanidinoacetate/
creatinine

< or =0.039

< or =0.036

< or =0.039

< or =0.036

< or =0.039

< or =0.036

 

 

57 Years

58 Years

59 Years

Female

Male

Female

Male

Female

Male

Creatine

19.2-52.9

12.7-34.4

19.9-53.1

12.8-34.3

20.5-53.3

12.8-34.2

Creatinine

37.3-84.9

49.8-105.4

37.4-85.1

49.8-105.5

37.6-85.2

49.8-105.6

Guanidinoacetate

1.2-3.0

1.6-3.2

1.3-3.0

1.6-3.2

1.3-3.0

1.6-3.2

Creatine/
creatinine

< or =0.84

< or =0.40

< or =0.85

< or =0.41

< or =0.86

< or =0.42

Guanidinoacetate/
creatine

< or =0.098

< or =0.151

< or =0.096

< or =0.151

< or =0.095

< or =0.150

Guanidinoacetate/
creatinine

< or =0.039

< or =0.036

< or =0.038

< or =0.036

< or =0.038

< or =0.036

 

 

60 Years

61 Years

62 Years

Female

Male

Female

Male

Female

Male

Creatine

21.0-53.6

12.8-34.1

21.5-53.9

12.7-34.0

21.9-54.2

12.6-33.9

Creatinine

37.8-85.4

49.9-105.7

38.0-85.5

49.9-105.9

38.3-85.7

49.9-106.0

Guanidinoacetate

1.3-2.9

1.6-3.2

1.3-2.9

1.6-3.1

1.3-2.9

1.6-3.1

Creatine/
creatinine

< or =0.87

< or =0.43

< or =0.87

< or =0.44

< or =0.88

< or =0.44

Guanidinoacetate/
creatine

< or =0.094

< or =0.150

< or =0.093

< or =0.150

< or =0.093

< or =0.150

Guanidinoacetate/
creatinine

< or =0.037

< or =0.036

< or =0.036

< or =0.035

< or =0.036

< or =0.035

 

 

63 Years

64 Years

65 Years

Female

Male

Female

Male

Female

Male

Creatine

22.2-54.6

12.4-33.7

22.3-55.0

12.3-33.6

22.5-55.5

12.2-33.4

Creatinine

38.7-85.8

50.0-106.1

39.1-85.9

50.0-106.3

39.6-86.1

50.1-106.4

Guanidinoacetate

1.3-2.8

1.6-3.1

1.3-2.8

1.6-3.1

1.3-2.8

1.6-3.1

Creatine/
creatinine

< or =0.88

< or =0.45

< or =0.89

< or =0.46

< or =0.89

< or =0.46

Guanidinoacetate/
creatine

< or =0.092

< or =0.150

< or =0.092

< or =0.149

< or =0.091

< or =0.149

Guanidinoacetate/
creatinine

< or =0.035

< or =0.035

< or =0.034

< or =0.034

< or =0.034

< or =0.034

 

 

66 Years

67 Years

68 Years

Female

Male

Female

Male

Female

Male

Creatine

22.6-55.9

12.3-33.1

22.7-56.3

12.3-32.8

22.9-56.7

12.5-32.4

Creatinine

40.2-86.2

50.2-106.6

40.7-86.3

50.3-106.7

41.3-86.5

50.4-106.9

Guanidinoacetate

1.3-2.7

1.6-3.1

1.3-2.7

1.6-3.0

1.4-2.7

1.6-3.0

Creatine/
creatinine

< or =0.90

< or =0.47

< or =0.90

< or =0.48

< or =0.90

< or =0.48

Guanidinoacetate/
creatine

< or =0.091

< or =0.149

< or =0.090

< or =0.148

< or =0.090

< or =0.148

Guanidinoacetate/
creatinine

< or =0.034

< or =0.034

< or =0.033

< or =0.034

< or =0.033

< or =0.034

 

 

69 Years

70 Years

> or = 71 Years

Female

Male

Female

Male

Female

Male

Creatine

23.2-57.0

12.8-32.0

23.6-57.2

13.1-31.4

24.1-57.3

13.6-30.8

Creatinine

41.9-86.6

50.5-107.1

42.4-86.8

50.7-107.4

42.8-86.9

50.8-107.6

Guanidinoacetate

1.4-2.6

1.6-3.0

1.4-2.6

1.6-3.0

1.4-2.5

1.5-3.0

Creatine/
creatinine

< or =0.90

< or =0.48

< or =0.90

< or =0.48

< or =0.90

< or =0.48

Guanidinoacetate/
creatine

< or =0.090

< or =0.148

< or =0.090

< or =0.148

< or =0.090

< or =0.148

Guanidinoacetate/
creatinine

< or =0.033

< or =0.034

< or =0.033

< or =0.034

< or =0.033

< or =0.034

Interpretation
Provides information to assist in interpretation of the test results

Reports include concentrations of guanidinoacetate, creatine, and creatinine, and the calculated analyte ratios. 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.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Creatine supplementation will cause falsely elevated creatine results and falsely decreased guanidinoacetate results.

 

Guanidinoacetate can be elevated in patients with urea cycle defects.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Clark JF, Cecil KM: Diagnostic methods and recommendations for the cerebral creatine deficiency syndromes. Pediatr Res; 2015 Mar;77(3):398-405

2. Mercimek-Mahmutoglu S, Salomons GS: Creatine deficiency syndromes. In: Pagon RA, Adam MP, Ardinger HH, et al. eds. GeneReviews [Internet]. University of Washington, Seattle; Jan 15 2009. Updated 2015 Dec 10. Accessed 2019 Dec 4. Available at www.ncbi.nlm.nih.gov/books/NBK3794/

3. Stockler S, Schultz PW, Salomons GS: Cerebral creatine deficiency syndromes: clinical aspects, treatment, and pathophysiology. Subcell Biochem. 2007;46:149-166

4. Longo N, Ardon O, Vanzo R, et al: Disorders of creatine transport and metabolism. Am J Med Genet. 2011;157:72-78 doi: 10.1002/ajmg.c.30292

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

A plasma sample is combined with stable isotope-labeled internal standards and acetonitrile. After centrifugation, an aliquot of this diluted sample is analyzed by injection onto liquid chromatography columns that separate the analytes from the bulk of the stable isotope dilution in the positive electrospray selected reaction monitoring mode using the Applied Biosystems API 3200 liquid chromatography-tandem mass spectrometry (LC-MS/MS) System with Analyst Software.(Bodamer OA, Bloesch SM, Gregg AR, et al: Analysis of guanidinoacetate and creatine by isotope dilution electroscopy tandem mass spectrometry. Clin Chim Acta. 2001;308:173-178; Cognat S, Cheillan D, Piraud M, et al: Determination of guanidinoacetate and creatine in urine and plasma by liquid chromatography-tandem mass spectrometry. Clin Chem. 2004;50:1459-1461; Sharer JD, Bodamer O, Longo N, Tortorelli S, Wamelink M, Young S: Laboratory diagnosis of creatine deficiency syndromes: a technical standard and guideline of the American College of Medical Genetics and Genomics. Genet Med. 2017 Feb;19[2]:256-263)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Tuesday; 12 p.m.

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 9 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 month

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

82540

82565

82542

LOINC® Information

Test Id Test Order Name Order LOINC Value
CRDPP Creatine Disorders Panel, P In Process
Result Id Test Result Name Result LOINC Value
Result LOINC Value Tooltip
608071 Interpretation 59462-2
608072 Creatine 15045-8
608073 Creatinine 14682-9
608074 Guanidinoacetate 33244-5
608075 Creatine/Creatinine In Process
610624 Guanidinoacetate/Creatine In Process
610856 Guanidinoacetate/Creatinine In Process
608076 Reviewed By 18771-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports