Acylcarnitine C4, Ur
Test Mnemonic
UC4
CPT Codes
- 82017 - QTY (1)
LOINC ®
53111-1
Aliases
- Butyrylcarnitine
- IBDH (Isobutyryl-CoA Dehydrogenase) Deficiency
- Isobutyryl
- Isobutyrylcarnitine
- Isobutyryl-CoA Dehydrogenase (IBDH) Deficiency
- Short Chain Acyl-CoA Dehydrogenase (SCAD) Deficiency
Includes
- C4 Acylcarnitine, QN, U
Performing Laboratory
Mayo Clinic Dpt of Lab Med & Pathology
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 5 mL | Urine, random | Clean container | Refrigerate ASAP | Frozen | Collect urine in clean plastic container. Please include family history, clinical condition, diet and drug therapy, if any. Freeze immediately. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | Unacceptable |
| Refrigerated | 24 hours |
| Frozen | 1 week |
Days Performed
Mon, Wed, Fri
Turnaround Time
3 - 6 days (Not reported on Sunday)
Methodology
| Name | Description |
|---|---|
| Flow Injection Analysis-Tandem Mass Spectrometry (FIA-MS/MS) |
Reference Range
| Acylcarnitine C4, Ur | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Normal | < 3.00 | mmol/mol crt |
Special Info
If clinically feasible, discontinue L-carnitine supplementation at least 72 hours before specimen collection. This test is New York DOH approved.
Clinical Info
Almost all patients with isobutyryl-CoA dehydrogenase deficiency excrete an abnormal amount of C4 in their urine. Some, but not all, affected individuals also excrete elevated levels of isobutyrylglycine. Conversely, patients with short-chain acyl-CoA dehydrogenase deficiency can have a normal excretion of C4.