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Order Code SSCTU S-Sulfocysteine Panel, Urine


Ordering Guidance


This is the recommended test when clinical features are suggestive of, or when molecular testing results suggest, molybdenum cofactor deficiency, isolated sulfite oxidase deficiency, and hereditary xanthinuria. This test includes measurement of relevant purines in addition to urine S-sulfocysteine and uric acid. If the clinical features are suggestive of a purine and pyrimidine metabolism disorder or are nonspecific, order PUPYU / Purine and Pyrimidines Panel, Random, Urine.

  This test will be canceled if ordered with PUPYU.

Necessary Information


Patient's age is required.



Specimen Required


Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 3 mL

Collection Instructions: Collect a random urine specimen.


Useful For

Diagnosis of molybdenum cofactor deficiency, isolated sulfite oxidase deficiency, and hereditary xanthinuria

 

Monitoring patients with molybdenum cofactor deficiency or isolated sulfite oxidase deficiency who are on treatment

Method Name

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

Reporting Name

S-Sulfocysteine Panel, U

Specimen Type

Urine

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen 90 days

Reject Due To

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

Reference Values

 

0-3 years

4-6 years

7-12 years

13-18 years

>18 years

Hypoxanthine

≤65

≤30

≤30

≤30

≤30

Xanthine

≤54

≤21

≤35

≤15

≤20

Uric Acid

350-2500

200-2000

200-1400

150-700

70-700

S-Sulfocysteine

≤11

≤5

≤5

≤5

≤5

 

All results reported as mmol/mol creatinine

Method Description

Diluted, filtered urine is mixed with an internal standard mixture and analyzed for hypoxanthine, xanthine, uric acid and S-sulfocysteine by liquid chromatography-tandem mass spectrometry. The ratios of the extracted peak areas of the purine and pyrimidine analytes to the added internal standards are used to calculate the concentration of purines and pyrimidines present in the sample.(la Marca G, Casetta B, Malvagia S, et al. Implementing tandem mass spectrometry as a routine tool for characterizing the complete purine and pyrimidine metabolic profile in urine samples. J Mass Spectrom. 2006;41[11]:1442-1452; Rashed MS, Saadallah AAA, Rahbeeni Z, et al. Determination of urinary S-sulphocysteine, xanthine and hypoxanthine by liquid chromatography-electrospray tandem mass spectrometry. Biomed Chromatogr. 2005;19[3]:223-230; Monostori P, Klinke G, Hauke J, et al. Extended diagnosis of purine and pyrimidine disorders from urine: LC MS/MS assay development and clinical validation. PLoS One. 2019;14[2]:e0212458. doi:10.1371/journal.pone.0212458)

Day(s) Performed

Tuesday, Thursday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82542