Evaluating patients with a clinical suspicion of arginine:glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency using plasma specimens
This test is not useful for the diagnosis of creatine transporter deficiency.
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, aids in distinguishing the types of creatine deficiency syndromes.
Treatment with oral creatine supplementation is effective in some types of CDS.
For more information see:
-Newborn Screen Follow-up for Guanidinoacetate Methyltransferase Deficiency (GAMT)
-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
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)
For more information see:
-Newborn Screen Follow-up for Guanidinoacetate Methyltransferase Deficiency (GAMT)
-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm
Plasma
To diagnose all creatine deficiency syndromes, order CRDPU / Creatine Disorders Panel, Random, Urine in addition to this test.
Patient's age and sex are required.
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.
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
0.1 mL
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma | Frozen (preferred) | 14 days | |
Refrigerated | 7 days | ||
Ambient | 72 hours |
Evaluating patients with a clinical suspicion of arginine:glycine amidinotransferase deficiency and guanidinoacetate methyltransferase deficiency using plasma specimens
This test is not useful for the diagnosis of creatine transporter deficiency.
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, aids in distinguishing the types of creatine deficiency syndromes.
Treatment with oral creatine supplementation is effective in some types of CDS.
For more information see:
-Newborn Screen Follow-up for Guanidinoacetate Methyltransferase Deficiency (GAMT)
-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm
Disorders of creatine synthesis (guanidinoacetate methyltransferase [GAMT] deficiency, L-arginine:glycine amidinotransferases [AGAT] deficiency, 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.
Creatine Disorders Panel Reference Values | ||||||||||||
| < 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/ | < or =3.07 | < or =3.60 | < or =3.02 | < or =3.54 | < or =2.96 | < or =3.48 | ||||||
Guanidinoacetate/ | < or =0.040 | < or =0.040 | < or =0.042 | < or =0.040 | < or =0.043 | < or =0.042 | ||||||
Guanidinoacetate/ | < 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/ | < or =2.89 | < or =3.40 | < or =2.77 | < or =3.26 | < or =2.64 | < or =3.09 | ||||||
Guanidinoacetate/ | < or =0.045 | < or =0.043 | < or =0.049 | < or =0.045 | < or =0.053 | < or =0.049 | ||||||
Guanidinoacetate/ | < 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/ | < or =2.49 | < or =2.91 | < or =2.33 | < or =2.70 | < or =2.17 | < or =2.49 |
Guanidinoacetate/ | < or =0.058 | < or =0.053 | < or =0.063 | < or =0.058 | < or =0.069 | < or =0.064 |
Guanidinoacetate/ | < 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/ | < or =2.02 | < or =2.28 | < or =1.86 | < or =2.07 | < or =1.72 | < or =1.87 |
Guanidinoacetate/ | < or =0.075 | < or =0.070 | < or =0.081 | < or =0.078 | < or =0.087 | < or =0.085 |
Guanidinoacetate/ | < 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/ | < or =1.58 | < or =1.68 | < or =1.45 | < or =1.50 | < or =1.33 | < or =1.34 |
Guanidinoacetate/ | < or =0.092 | < or =0.093 | < or =0.097 | < or =0.101 | < or =0.101 | < or =0.109 |
Guanidinoacetate/ | < 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/ | < or =1.22 | < or =1.20 | < or =1.12 | < or =1.07 | < or =1.04 | < or =0.97 |
Guanidinoacetate/ | < or =0.104 | < or =0.117 | < or =0.107 | < or =0.125 | < or =0.109 | < or =0.132 |
Guanidinoacetate/ | < 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/ | < or =0.98 | < or =0.87 | < or =0.93 | < or =0.80 | < or =0.89 | < or =0.73 |
Guanidinoacetate/ | < or =0.111 | < or =0.139 | < or =0.112 | < or =0.145 | < or =0.113 | < or =0.150 |
Guanidinoacetate/ | < 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/ | < or =0.87 | < or =0.68 | < or =0.85 | < or =0.64 | < or =0.84 | < or =0.61 |
Guanidinoacetate/ | < or =0.114 | < or =0.156 | < or =0.115 | < or =0.161 | < or =0.116 | < or =0.165 |
Guanidinoacetate/ | < 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/ | < or =0.84 | < or =0.58 | < or =0.84 | < or =0.56 | < or =0.84 | < or =0.54 |
Guanidinoacetate/ | < or =0.116 | < or =0.170 | < or =0.117 | < or =0.174 | < or =0.118 | < or =0.179 |
Guanidinoacetate/ | < 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/ | < or =0.84 | < or =0.52 | < or =0.84 | < or =0.51 | < or =0.84 | < or =0.49 |
Guanidinoacetate/ | < or =0.118 | < or =0.182 | < or =0.119 | < or =0.186 | < or =0.119 | < or =0.188 |
Guanidinoacetate/ | < 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/ | < or =0.84 | < or =0.48 | < or =0.83 | < or =0.47 | < or =0.83 | < or =0.46 |
Guanidinoacetate/ | < or =0.120 | < or =0.190 | < or =0.120 | < or =0.192 | < or =0.119 | < or =0.192 |
Guanidinoacetate/ | < 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/ | < or =0.82 | < or =0.45 | < or =0.82 | < or =0.45 | < or =0.82 | < or =0.44 |
Guanidinoacetate/ | < or =0.119 | < or =0.192 | < or =0.118 | < or =0.191 | < or =0.118 | < or =0.189 |
Guanidinoacetate/ | < 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/ | < or =0.82 | < or =0.44 | < or =0.82 | < or =0.44 | < or =0.83 | < or =0.44 |
Guanidinoacetate/ | < or =0.117 | < or =0.187 | < or =0.115 | < or =0.184 | < or =0.114 | < or =0.182 |
Guanidinoacetate/ | < 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/ | < or =0.83 | < or =0.44 | < or =0.83 | < or =0.44 | < or =0.84 | < or =0.44 |
Guanidinoacetate/ | < or =0.113 | < or =0.179 | < or =0.111 | < or =0.176 | < or =0.110 | < or =0.174 |
Guanidinoacetate/ | < 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/ | < or =0.84 | < or =0.44 | < or =0.84 | < or =0.43 | < or =0.84 | < or =0.43 |
Guanidinoacetate/ | < or =0.109 | < or =0.172 | < or =0.108 | < or =0.171 | < or =0.107 | < or =0.170 |
Guanidinoacetate/ | < 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/ | < or =0.84 | < or =0.42 | < or =0.83 | < or =0.41 | < or =0.83 | < or =0.40 |
Guanidinoacetate/ | < or =0.106 | < or =0.169 | < or =0.106 | < or =0.168 | < or =0.106 | < or =0.167 |
Guanidinoacetate/ | < 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/ | < or =0.82 | < or =0.39 | < or =0.82 | < or =0.38 | < or =0.82 | < or =0.38 |
Guanidinoacetate/ | < or =0.106 | < or =0.166 | < or =0.106 | < or =0.164 | < or =0.105 | < or =0.163 |
Guanidinoacetate/ | < 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/ | < or =0.82 | < or =0.37 | < or =0.82 | < or =0.37 | < or =0.82 | < or =0.38 |
Guanidinoacetate/ | < or =0.105 | < or =0.161 | < or =0.104 | < or =0.159 | < or =0.103 | < or =0.157 |
Guanidinoacetate/ | < 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/ | < or =0.82 | < or =0.38 | < or =0.83 | < or =0.39 | < or =0.84 | < or =0.40 |
Guanidinoacetate/ | < or =0.102 | < or =0.155 | < or =0.100 | < or =0.154 | < or =0.099 | < or =0.152 |
Guanidinoacetate/ | < 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/ | < or =0.84 | < or =0.40 | < or =0.85 | < or =0.41 | < or =0.86 | < or =0.42 |
Guanidinoacetate/ | < or =0.098 | < or =0.151 | < or =0.096 | < or =0.151 | < or =0.095 | < or =0.150 |
Guanidinoacetate/ | < 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/ | < or =0.87 | < or =0.43 | < or =0.87 | < or =0.44 | < or =0.88 | < or =0.44 |
Guanidinoacetate/ | < or =0.094 | < or =0.150 | < or =0.093 | < or =0.150 | < or =0.093 | < or =0.150 |
Guanidinoacetate/ | < 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/ | < or =0.88 | < or =0.45 | < or =0.89 | < or =0.46 | < or =0.89 | < or =0.46 |
Guanidinoacetate/ | < or =0.092 | < or =0.150 | < or =0.092 | < or =0.149 | < or =0.091 | < or =0.149 |
Guanidinoacetate/ | < 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/ | < or =0.90 | < or =0.47 | < or =0.90 | < or =0.48 | < or =0.90 | < or =0.48 |
Guanidinoacetate/ | < or =0.091 | < or =0.149 | < or =0.090 | < or =0.148 | < or =0.090 | < or =0.148 |
Guanidinoacetate/ | < 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/ | < or =0.90 | < or =0.48 | < or =0.90 | < or =0.48 | < or =0.90 | < or =0.48 |
Guanidinoacetate/ | < or =0.090 | < or =0.148 | < or =0.090 | < or =0.148 | < or =0.090 | < or =0.148 |
Guanidinoacetate/ | < or =0.033 | < or =0.034 | < or =0.033 | < or =0.034 | < or =0.033 | < or =0.034 |
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.
Creatine supplementation will cause falsely elevated creatine results and falsely decreased guanidinoacetate results.
Guanidinoacetate can be elevated in patients with urea cycle defects.
1. Clark JF, Cecil KM. Diagnostic methods and recommendations for the cerebral creatine deficiency syndromes. Pediatr Res. 2015;77(3):398-405
2. Mercimek-Mahmutoglu S, Salomons GS. Creatine deficiency syndromes. In: Adam MP, Mirzaa GM, Pagon RA, et al. eds. GeneReviews [Internet]. University of Washington, Seattle; 2009. Updated February 10, 2022. Accessed March 30, 2023. 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
Tuesday
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.
82540
82565
82542
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
CRDPP | Creatine Disorders Panel, P | In Process |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
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 |
Change Type | Effective Date |
---|---|
New Test | 2021-08-24 |