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Test Code ALAD Aminolevulinic Acid Dehydratase, Whole Blood

Reporting Name

ALA Dehydratase, WB

Useful For

Preferred confirmation test for the diagnosis of aminolevulinic acid dehydratase deficiency porphyria

 

This test is not useful for detecting lead intoxication.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Whole blood


Ordering Guidance


This assay is not useful in assessment of lead intoxication as it reactivates aminolevulinic acid dehydratase that has been inhibited by lead. The preferred test for lead toxicity is PBDV / Lead, Venous, with Demographics, Blood.



Necessary Information


1. Patient’s age is required

2. Include a list of medications the patient is currently taking.



Specimen Required


Patient Preparation: Patient must not consume any alcohol for 24 hours before specimen collection. This is essential as ethanol suppresses aminolevulinic acid dehydratase activity, leading to false-positive results.

Container/Tube:

Preferred: Green top (sodium heparin)

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

Specimen Volume: Full tube 4 mL

Collection Instructions: Refrigerate specimen as soon as possible.


Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated (preferred) 7 days
  Ambient  4 days

Reference Values

Reference ranges have not been established for patients who are younger than 16 years of age.

 

≥4.0 nmol/L/sec

3.5-3.9 nmol/L/sec (indeterminate)

<3.5 nmol/L/sec (diminished)

Day(s) Performed

Thursday

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

82657

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ALAD ALA Dehydratase, WB 12916-3

 

Result ID Test Result Name Result LOINC Value
4021 ALA Dehydratase 12916-3
28399 Interpretation 59462-2
606468 Reviewed By 18771-6

Interpretation

Abnormal results are reported with a detailed interpretation including an overview of the results and their significance, a correlation to available clinical information provided with the specimen, differential diagnosis, and recommendations for additional testing when indicated and available.

Clinical Reference

1. Tortorelli S, Kloke K, Raymond K. 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

2. Nuttall KL, Klee GG. Analytes of hemoglobin metabolism-porphyrins, iron, and bilirubin. In: Burtis CA, Ashwood ER, eds. Tietz Textbook of Clinical Chemistry. 5th ed. WB Saunders Company; 2001:584-607

3. Anderson KE, Sassa S, Bishop DF, Desnick RJ. Disorders of heme biosynthesis: X-linked sideroblastic anemia and the porphyrias. In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill, 2019. Accessed April 19, 2024. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225540906&bookid=2709

4. Lahiji AP, Anderson KE, Chan A. 5-Aminolevulinate dehydratase porphyria: Update on hepatic 5-aminolevulinic acid synthase induction and long-term response to hemin. Mol Genet Metab. 2020;131(4):418-423. doi:10.1016/j.ymgme.2020.10.011

Report Available

2 to 8 days

Method Name

Enzymatic End point/Spectrofluorometric

Forms

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:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)