Porphobilinogen (PBG) Deaminase, Erythrocyte
Also known as: PBG-D
Use
This test is used to confirm a diagnosis of acute intermittent porphyria (AIP) following a positive urine porphobilinogen (PBG) test. It is also used to evaluate disease risk in family members of an individual with a confirmed diagnosis of AIP. In genetically susceptible individuals, PBG deaminase concentrations are approximately half of reference values. Normal concentrations of erythrocyte PBG deaminase may include abnormal forms of hepatic PBG deaminase.
Special Instructions
This test is most useful for family studies to determine which family members are at risk for acute intermittent porphyria and is best performed in association with a specimen from the proband. Due to potentially ambiguous results, it is not generally recommended for primary diagnosis.
Limitations
The PBG deaminase assay has limitations in that it is not generally recommended for initial diagnosis of acute intermittent porphyria due to the possibility of ambiguous results. Elevated PBG deaminase levels may suggest a young population of red blood cells secondary to hemolysis, which is not consistent with acute intermittent porphyria.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 49228-0
Result Turnaround Time
1-6 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Lavender (EDTA) or pink (K2EDTA)
Patient Preparation
Perform automated hemoglobin on EDTA whole blood before preparing for transport.
Storage Instructions
Frozen
Causes for Rejection
Body fluid other than EDTA preserved whole blood. Clotted specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |
| Refrigerated | 1 week |
| Frozen | 1 month |