Cerebrotendinous Xanthomatosis, Plasma
Use
This test is useful for evaluating patients with a clinical suspicion of cerebrotendinous xanthomatosis (CTX) using plasma specimens. It monitors individuals with CTX on chenodeoxycholic acid (CDCA) therapy. Cerebrotendinous xanthomatosis is an autosomal recessive disorder of bile acid synthesis resulting from the deficiency of the mitochondrial enzyme sterol 27-hydrolase, leading to increased storage of sterol and bile acid precursors and deficiency of chenodeoxycholic acid, causing a variety of clinical symptoms.
Special Instructions
The test is performed on plasma specimens, preferably collected in a lavender top (EDTA) tube. It is not useful for identifying carriers or evaluating bile acid malabsorption. The test must be ordered individually, as it will be canceled and substituted with the Hepatosplenomegaly Panel if ordered together with specific other tests like Glucopsychosine or Oxysterols, Plasma.
Limitations
This test should not be used for the identification of CTX carriers nor for evaluating bile acid malabsorption. Patients with bile acid malabsorption or ileal resection may have elevations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4) that might complicate interpretation. It is not FDA approved but developed in accordance with CLIA guidelines.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 92746-7
- 59462-2
- 92761-6
- 92758-2
- 18771-6
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
0.3 mL
Minimum Volume
0.25 mL
Container
Plastic vial
Collection Instructions
Centrifuge at 4 degrees C if possible, aliquot plasma into a plastic vial without disturbing the buffy coat, and send frozen.
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 65 days |