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Epic Code LAB848 Hyperoxaluria Panel, Random, Urine

Important Note

Order as Reference Miscellaneous #LAB848; indicate complete test name when ordering.

Additional Codes

Mayo Code: HYOX

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Distinguishing between primary and secondary hyperoxaluria

 

Distinguishing between primary hyperoxaluria types 1, 2, and 3

Specimen Type

Urine


Necessary Information


1. Patient age is required.

2. Biochemical Genetics Patient Information (T602) is recommended, but not required, to be filled out and sent with the specimen to aid in the interpretation of test results.



Specimen Required


Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 10 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.

3. Immediately freeze specimen.


Special Instructions

Specimen Minimum Volume

1.1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen (preferred) 90 days
  Refrigerated  14 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Day(s) Performed

Wednesday

Reference Values

GLYCOLATE

≤17 years: ≤75 mg/g creatinine

≥18 years: ≤50 mg/g creatinine

 

GLYCERATE

≤31 days: ≤75 mg/g creatinine

32 days - 4 years: ≤125 mg/g creatinine

5 - 10 years: ≤55 mg/g creatinine

≥11 years: ≤25 mg/g creatinine

 

OXALATE

≤6 months: ≤400 mg/g creatinine

7 months - 1 year: ≤300 mg/g creatinine

2 - 6 years: ≤150 mg/g creatinine

7 - 10 years: ≤100 mg/g creatinine

≥11 years: ≤75 mg/g creatinine

 

4-HYDROXY-2-OXOGLUTARATE (HOG)

≤10 mg/g creatinine

Clinical Information

Increased urinary oxalate frequently leads to kidney stone formation and kidney insufficiency. Identifying the cause of hyperoxaluria has important implications in therapy, management, and prognosis.

 

Hyperoxalurias are classified as primary and secondary. Primary hyperoxaluria is an inherited disorder of oxalate metabolism, while secondary hyperoxaluria is an acquired condition resulting from either increased intake of dietary oxalate or altered intestinal oxalate absorption. Primary hyperoxalurias are classified into types 1, 2, and 3.

 

Hyperoxaluria type 1 (PH1) is an autosomal recessive disorder resulting in a deficiency of peroxisomal alanine:glyoxylate aminotransferase due to variants in the AGXT gene. It is characterized by increased urinary oxalic, glyoxylic, and glycolic acids. PH1 is the most common type with manifestations that include deposition of calcium oxalate in the kidneys (nephrolithiasis, nephrocalcinosis) and kidney failure. Calcium oxalate deposits can be further deposited in other tissues, such as the heart and eyes, and lead to a variety of additional symptoms. Age of onset is variable with a small percentage of patients presenting in the first year of life with failure to thrive, nephrocalcinosis, and metabolic acidosis. Approximately half of affected individuals show manifestations of PH1 in late childhood or early adolescence, and the remainder present in adulthood with recurrent kidney stones. Some individuals with PH1 respond to supplemental pyridoxine therapy.

 

Hyperoxaluria type 2 (PH2) is due to a defect in GRHPR gene resulting in a deficiency of the enzyme hydroxypyruvate reductase. PH2 is inherited in an autosomal recessive manner and is identified by an increase in urinary oxalic and glyceric acids. Like PH1, PH2 is characterized by deposition of calcium oxalate in the kidneys (nephrolithiasis, nephrocalcinosis), and kidney failure. Most individuals have symptoms of PH2 during childhood, and it is thought that PH2 is less common than PH1.

 

Hyperoxaluria type 3 (PH3), due to recessive variants in HOGA1 (formerly DHDPSL), occurs in a small percentage of individuals with primary hyperoxaluria. HOGA1 encodes a mitochondrial 4-hydroxy-2-oxoglutarate aldolase that catalyzes the 4th step in the hydroxyproline pathway. PH3 is characterized biochemically by increased urinary excretion of oxalate and 4-hydroxy-2-oxoglutarate (HOG). As with PH types 1 and 2, PH type 3 is characterized by calcium-oxalate deposition in the kidneys or kidney stone formation. Most individuals with PH3 have early onset disease with recurrent kidney stones and urinary tract infections as common symptoms. Kidney failure is not a characteristic of PH3. Of note, individuals with heterozygous variants in HOGA1 can have variable and intermittent elevations of urine oxalate.

 

Secondary hyperoxalurias are due to hyperabsorption of oxalate (enteric hyperoxaluria); total parenteral nutrition in premature infants; ingestion of oxalate, ascorbic acid, or ethylene glycol; or pyridoxine deficiency, and may respond to appropriate therapy.

 

A diagnostic workup in an individual with hyperoxaluria demonstrates increased concentration of oxalate in urinary metabolite screening. If glycolate, glycerate, or HOG is present, a primary hyperoxaluria is indicated. Confirmatory testing includes molecular analysis for PH1, PH2, or PH3 (CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies; refer to the Hyperoxaluria Diagnostic Algorithm for specific Gene List IDs).

Cautions

Ascorbic acid (vitamin C) will falsely elevate oxalic acid results.

Interpretation

Increased concentrations of oxalate and glycolate indicate type 1 hyperoxaluria.

 

Increased concentrations of oxalate and glycerate indicate type 2 hyperoxaluria.

 

Increased concentrations of oxalate and 4-hydroxy-2-oxoglutarate indicate type 3 hyperoxaluria.

 

Increased concentrations of oxalate with normal concentrations of glycolate, glycerate, and 4-hydroxy-2-oxoglutarate indicate secondary hyperoxaluria.

Reporting Name

Hyperoxaluria Panel, U

Method Name

Gas Chromatography Mass Spectrometry (GC-MS)

Method Description

Urine samples corresponding to 0.25 mg of creatinine (not to exceed 1 mL of urine) are oximated to stabilize one of the target analytes, 4-hydroxy-2-oxoglutaric. The urine is then acidified and extracted. After evaporation, the dry residue is silylated and analyzed by capillary gas chromatography mass spectrometry.(Unpublished Mayo method)

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HYOX Hyperoxaluria Panel, U 53710-0

 

Result ID Test Result Name Result LOINC Value
50592 Glycolate 13751-3
50593 Glycerate 13749-7
50594 Oxalate 13483-3
38049 4-hydroxy-2-oxoglutarate 13678-8
29982 Interpretation 59462-2
29984 Reviewed By 18771-6

Report Available

3 to 9 days

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.

Clinical Reference

1. Bhasin B, Urekli HM, Atta MG. Primary and secondary hyperoxaluria: Understanding the enigma. World J Nephrol. 2015;4(2):235-244. doi:10.5527/wjn.v4.i2.235

2. Lorenzo V, Torres A, Salido E. Primary hyperoxaluria. Nefrologia. 2014;34(3):398-412

3. Milliner DS, Harris PC, Cogal AG, et al. Primary hyperoxaluria type 1. In: Adam MP, Mirzaa GM, Pagon RA, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2002. Updated February 10, 2022. Accessed August 28, 2023. Available at: www.ncbi.nlm.nih.gov/books/NBK1283/

4. Rumsby G, Hulton SA. Primary hyperoxaluria type 2. In: Adam MP, Mirzaa GM, Pagon RA, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2008. Updated December 21, 2017. Accessed August 28, 2023. Available at: www.ncbi.nlm.nih.gov/books/NBK2692/

5. Milliner DS, Harris PC, Lieske JC. Primary hyperoxaluria type 3. In: Adam MP, Mirzaa GM, Pagon RA, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2015. Updated February 9, 2023. Accessed August 28, 2023. Available at: www.ncbi.nlm.nih.gov/books/NBK316514/

6. Fraser AD: Importance of glycolic acid analysis in ethylene glycol poisoning. Clin Chem. 1998;44(8):1769

Highlights

A diagnostic workup in an individual with hyperoxaluria demonstrates increased concentration of oxalate in urinary metabolite screening. If glycolate, glycerate, or 4-hydroxy-2-oxoglutarate is present, a primary hyperoxaluria is indicated.

 

Each type of primary hyperoxaluria is distinguished from the others based on the urine profile.

Forms

1. Biochemical Genetics Patient Information (T602)

2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Biochemical Genetics Test Request (T798)

-Renal Diagnostics Test Request (T830)