ARUP's Laboratory Test Directory

Porphobilinogen (PBG) Deaminase, Erythrocyte : 0099550

Mnemonic: PBG-D

Methodology: Quantitative Enzymatic/Fluorometry
Performed: Tue, Fri
Reported: 1-5 days
Specimen Required: Collect: Lavender (EDTA) or pink (K2EDTA).

Specimen Preparation: Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature: Frozen.

Unacceptable Conditions: Body fluid other than EDTA preserved whole blood. Clotted specimens.

Stability (collection to initiation of testing): Ambient: 4 hours; Refrigerated: 1 week; Frozen: 1 month
Reference Interval:
Adult: 2.10-4.30 mU/g Hb
Interpretive Data: Porphobilinogen (PBG) deaminase (hydroxymethylbilane synthase or uroporphyrinogen I synthase) is expressed in units of mU per gram hemoglobin at 37°C. In persons genetically susceptible to acute intermittent porphyria (AIP), PBG deaminase concentrations are approximately half of reference values. Normal concentrations of erythrocyte PBG deaminase may include abnormal forms of hepatic PBG deaminase.
Note: This test is most useful for family studies to determine which family members are at risk for acute intermittent porphyria.  It is best performed in association with a specimen from the proband.  Because of ambiguous results, this test is not generally recommended for diagnosis of individuals.
CPT Code(s): 82657
Cross References: Acute Intermittent Porphyria Enzyme (Phorphobilinogen (PGB) Deaminase, Erythrocyte), Hydroxymethylbilane Synthase (Phorphobilinogen (PGB) Deaminase, Erythrocyte), Porphyria Enzyme (Phorphobilinogen (PGB) Deaminase, Erythrocyte), Uroporphyrinogen I Synthase (Phorphobilinogen (PGB) Deaminase, Erythrocyte)