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Test 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

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

Interpretation

Abnormal concentrations of measurable compounds will be reported along with an interpretation. The interpretation of an abnormal metabolite pattern includes an overview of the results and of their significance, a correlation to available clinical information, possible differential diagnosis, recommendations for additional biochemical testing and confirmatory studies (enzyme assay, molecular analysis), name, and phone number of contacts who may provide these studies, and a phone number of the laboratory directors in case the referring physician has additional questions.

Clinical Reference

1. Melcher K, Mountford WK, Hoffmann GF, Ries M. Ultra-orphan diseases: a quantitative analysis of the natural history of molybdenum cofactor deficiency. Gen Med. 2015;17(12):965-970

2. Claerhout H, Witters P, Regal L, et al. Isolated sulfite oxidase deficiency. J Inherit Metab Dis. 2018;41(1):101-108

3. Misko AL, Liang Y, Kohl JB, Eichler F. Delineating the phenotypic spectrum of sulfite oxidase and molybdenum cofactor deficiency. Neurol Genet. 2020;6(4):e486

Day(s) Performed

Tuesday, Thursday

Report Available

3 to 7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SSCTU S-Sulfocysteine Panel, U 94397-7

 

Result ID Test Result Name Result LOINC Value
607007 Interpretation (SSCTU) 59462-2
607002 Hypoxanthine 38366-1
607003 Xanthine 38371-1
607004 Uric Acid 34385-5
607005 S-Sulfocysteine 33876-4
607006 Reviewed By 18771-6