Test Code CTSU Ceramide Trihexosides and Sulfatides, Random, Urine
Reporting Name
Ceramide Trihex and Sulfatide, UPerforming Laboratory
Mayo Clinic Laboratories in RochesterUseful For
Identifying patients with Fabry disease
Identifying patients with metachromatic leukodystrophy
Identifying patients with saposin B deficiency
Identifying patients with multiple sulfatase deficiency
Identifying patients with mucolipidosis II (I-cell disease)
Method Name
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS)
Necessary Information
Biochemical Genetics Patient Information (T602) is recommended. This information aids in providing a more thorough interpretation of results. Send information with specimen.
Specimen Required
Patient Preparation: Baby wipes or wipes containing soaps and lotions should not be used prior to urine collection because these may interfere with results.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plastic, 5-mL urine tube
Specimen Volume: 2 mL
Collection Instructions: Collect a first-morning, random urine specimen.
Specimen Stability Information: Refrigerated (preferred) 45 days/Ambient 45 days/Frozen 19 months
Specimen Type
UrineSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 45 days | |
Ambient | 45 days | ||
Frozen |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided.
Interpretation
The pattern of ceramide trihexosides or sulfatide excretion will be described. A normal pattern of excretion suggests absence of these diseases (see Cautions).
Evidence of ceramide trihexoside accumulation suggests decreased or deficient alpha-galactosidase activity, see Fabry Disease Testing Algorithm.
Evidence of sulfatide accumulation suggests decreased or deficient arylsulfatase A activity. Follow-up with the specific enzyme assay is recommended:
-ARSAW / Arylsulfatase A, Leukocytes
-ARSU / Arylsulfatase A, 24 Hour, Urine
To exclude multiple sulfatase deficiency (MSD), determination of iduronate-2-sulfatase activity is recommended.
-I2SWB / Iduronate-2-Sulfatase, Leukocytes
-I2SB / Iduronate-2-Sulfatase, Blood Spot
Evidence of both ceramide trihexoside and sulfatide accumulation suggests a diagnosis of mucolipidosis II (I-cell disease) or saposin B deficiency. Follow-up testing to rule-out I-cell disease may include molecular analysis of the GNPTAB gene or measurement of serum hydrolases (NAGS / Hexosaminidase A and Total Hexosaminidase, Serum).
Molecular genetic testing is required to confirm saposin B deficiency.
For more information see Lysosomal Storage Disorders Diagnostic Algorithm, Part 2.
Day(s) Performed
Monday
Report Available
8 to 15 daysTest 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
83789
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
CTSU | Ceramide Trihex and Sulfatide, U | 59462-2 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
606148 | Interpretation | 59462-2 |
606149 | Reviewed By | 18771-6 |
Forms
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Testing Algorithm
For information see:
-Fabry Disease Diagnostic Testing Algorithm
If the patient has abnormal newborn screening results for Fabry disease. Refer to the appropriate ACMG Newborn Screening ACT Sheet.(1)