Porphyrins Evaluation, WB
GTR Test Accession: Help GTR000613098.2
INHERITED DISEASECONNECTIVE TISSUEDIGESTIVE SYSTEM ... View more
Last updated in GTR: 2024-05-02
Last annual review date for the lab: 2024-05-28 LinkOut
At a Glance
Diagnosis; Screening
Erythropoietic protoporphyria; X-linked erythropoietic protoporphyria
Free protoporphyrin; Porphyrin; Zinc-complexed protoporphyrin
Biochemical Genetics - Analyte: Fluorometry
Establishing a biochemical diagnosis of erythropoietic protoporphyria and X-linked dominant …
Not provided
Establish or confirm diagnosis
Ordering Information
Offered by: Help
Test short name: Help
PEE
Specimen Source: Help
Who can order: Help
  • Genetic Counselor
  • Health Care Provider
  • Licensed Dentist
  • Licensed Physician
  • Nurse Practitioner
  • Physician Assistant
  • Public Health Mandate
  • Registered Nurse
Lab contact: Help
Gisele (Gessi) Bentz Pino, MS, CGC, Certified Genetic counselor, CGC, Genetic Counselor
biochemicalgenetics@mayo.edu
1-800-533-1710
Contact Policy: Help
Laboratory can only accept contact from health care providers. Patients/families are encouraged to discuss genetic testing options with their health care provider.
How to Order: Help
https://www.mayocliniclabs.com/test-catalog/overview/88886#Specimen
Order URL
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
Based on applicable state law
Pre-test genetic counseling required: Help
Decline to answer
Post-test genetic counseling required: Help
Decline to answer
Recommended fields not provided:
Conditions Help
Total conditions: 2
Condition/Phenotype Identifier
Test Targets
Analytes Help
Total analytes: 3
Analyte Associated Condition
Methodology
Total methods: 1
Method Category Help
Test method Help
Instrument *
Analyte
Fluorometry
* Instrument: Not provided
Clinical Information
Test purpose: Help
Diagnosis; Screening
Clinical utility: Help
Establish or confirm diagnosis
View citations (1)
  • Tortorelli S, Kloke K, Raymond K: Chapter 15: Disorders of porphyrin metabolism. In: Dietzen DG, Bennett MJ, Wong ECC, eds. Biochemical and Molecular Basis of Pediatric Disease. 4th ed. AACC Press; 2010:307-324

Target population: Help
Establishing a biochemical diagnosis of erythropoietic protoporphyria and X-linked dominant protoporphyria.
View citations (5)
Variant Interpretation:
What is the protocol for interpreting a variation as a VUS? Help
N/A

Will the lab re-contact the ordering physician if variant interpretation changes? Help
Not provided. N/A
Research:
Is research allowed on the sample after clinical testing is complete? Help
N/A
Recommended fields not provided:
Technical Information
Test Procedure: Help
This evaluation is performed as a 2-step analysis. First, the total red blood cell (RBC) porphyrin concentration is determined by extracting the porphyrins from washed, resuspended RBCs using a mixture of ethyl acetate and acetic acid. The porphyrins are then back extracted into dilute hydrochloric acid. Total porphyrins are quantified … View more
View citations (2)
  • Gou EW, Balwani M, Bissell DM, Bloomer JR, Bonkovsky HL, Desnick RJ, Naik H, Phillips JD, Singal AK, Wang B, Keel S, Anderson KE. Pitfalls in Erythrocyte Protoporphyrin Measurement for Diagnosis and Monitoring of Protoporphyrias. Clin Chem. 2015;61(12):1453-6. doi:10.1373/clinchem.2015.245456. Epub 2015 Oct 19. PMID: 26482161.
  • High-performance liquid chromatographic determination of protoporphyrin and zinc protoporphyrin in blood. Smith RM, et al. J Chromatogr. 1980;181(3-4):319-27. doi:10.1016/s0378-4347(00)81134-2. PMID: 7391148.
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
Accuracy was assessed by the analysis of proficiency testing specimens and was acceptable. Intra assay precision was performed at 3 levels: CV results ranged from 0.21% to 0.38% (N=5 each). Inter assay precision was performed at 2 levels: CV results were 5.7% and 3.9% (N=5 each). The analytical measurement range … View more
Assay limitations: Help
Alcohol suppresses enzyme activity potentially leading to false-positive results if it is ingested within 24 hours of specimen collection.
Proficiency testing (PT):
Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Formal PT program

PT Provider: Help
IPNET, RCPA, PA

Description of PT method: Help
Formal PT program.

Description of internal test validation method: Help
This test was laboratory developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements.
VUS:
Software used to interpret novel variations Help
N/A

Laboratory's policy on reporting novel variations Help
N/A
Recommended fields not provided:
Regulatory Approval
FDA Review: Help
Category: FDA exercises enforcement discretion
Additional Information

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