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Test ID UPGD Uroporphyrinogen Decarboxylase (UPG D), Whole Blood

Useful For

Preferred test for the confirmation of a diagnosis of porphyria cutanea tarda type II and hepatoerythropoietic porphyria

Genetics Test Information

Uroporphyrinogen decarboxylase (UPGD) is deficient in cases of type II porphyria cutanea tarda (PCT). Enzyme analysis is uninformative in sporadic PCT cases.

 

Due to longer specimen stability, this is the preferred test for analysis of UPGD enzyme.

Method Name

High-Performance Liquid Chromatography (HPLC)/Incubation of Lysed Erythrocytes

Reporting Name

UPG Decarboxylase, WB

Specimen Type

Whole blood


Advisory Information


Porphyria cutanea tarda (PCT) type I, the most common form of PCT, exhibits normal RBC enzyme activity. The preferred test for diagnosis of type I is PQNU / Porphyrins, Quantitative, 24 Hour, Urine or PQNRU / Porphyrins, Quantitative, Random, Urine.



Necessary Information


Include a list of medications the patient is currently taking.



Specimen Required


All porphyrin tests on whole blood can be performed on 1 draw tube.

 

Patient Preparation: Patient should abstain from alcohol for 24 hours

Container/Tube:

Preferred: Green top (sodium heparin)

Acceptable: Lavender top (EDTA) or light, green top (lithium heparin)

Specimen Volume: Full tube

Collection Instructions: Immediately place specimen on wet ice.


Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole blood Refrigerated 7 days

Reference Values

>1.0 Relative Units (normal)

0.80-0.99 Relative Units (indeterminate)

<0.80 Relative Units (porphyria cutanea tarda or hepatoerythropoietic porphyria)

Day(s) and Time(s) Performed

Tuesday; 8 a.m.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82657

LOINC Code Information

Test ID Test Order Name Order LOINC Value
UPGD UPG Decarboxylase, WB 49596-0

 

Result ID Test Result Name Result LOINC Value
8599 UPG Decarboxylase, WB 49596-0

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 U.S. Food and Drug Administration.

Testing Algorithm

The following algorithms are available in Special Instructions:

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.