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Test ID PBALP Porphobilinogen and Aminolevulinic Acid, Plasma

Shipping Instructions

Ship specimens refrigerated or frozen and in amber vial to protect from light.

Necessary Information

Include a list of medications the patient is currently taking.

Specimen Required

Patient Preparation: Patient should abstain from alcohol for at least 24 hours prior to specimen collection.

Supplies: Amber Frosted Tube, 5 mL (T192)

Collection Container/Tube:

Preferred: Green top (heparin)

Acceptable: Green top (lithium heparin), lavender top (EDTA), yellow top (ACD A or B)

Submission Container/Tube: Amber vial

Specimen Volume: 1 mL

Collection Instructions: It is recommended that specimen collection occur during the acute phase. Porphobilinogen (PBG) and aminolevulinic acid (ALA) may be normal when the patient is not exhibiting symptoms.

Useful For

An equivalent option to urine for first-line test for evaluation of a suspected acute porphyria


Monitoring patients undergoing treatment for an acute intermittent porphyria or other acute porphyria

Genetics Test Information

Plasma porphobilinogen (PBG) and aminolevulinic acid (ALA) are elevated during the symptomatic phase of the acute porphyrias: acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria


An isolated elevation of ALA may be due to the very rare aminolevulinic acid dehydratase deficiency porphyria (ADP) or more commonly, a secondary inhibition of ALA.


This test can be used as part of the diagnostic assessment and monitoring of patients with acute intermittent porphyria (AIP) and other acute porphyrias.


Results are most informative when the specimen is obtained while the patient is having symptoms.


Additional testing must be performed to distinguish among the acute porphyrias.


When a urine specimen cannot be obtained during a symptomatic episode, this test provides an alternative specimen collection for the evaluation of a suspected acute porphyria.

Testing Algorithm

The following algorithms are available in Special Instructions:

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Method Name

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

Reporting Name

PBG and ALA, P

Specimen Type


Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Frozen (preferred) 21 days LIGHT PROTECTED
  Refrigerated  7 days LIGHT PROTECTED

Reference Values

Porphobilinogen: ≤0.5 nmol/mL

Aminolevulinic Acid: ≤0.5 nmol/mL

Day(s) Performed


Report Available

2 to 9 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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



LOINC Code Information

Test ID Test Order Name Order LOINC Value
PBALP PBG and ALA, P 96911-3


Result ID Test Result Name Result LOINC Value
38029 Porphobilinogen, P 17474-8
38028 Aminolevulinic Acid, P 79646-6
38030 Interpretation (PBALP) 59462-2
38031 Reviewed By 18771-6

NY State Approved


Disease States

  • Porphyria