Test Details
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Result Turnaround Time
10 - 14 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Plasma Thymidine/Deoxyuridine analyte is used for diagnosis of Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). Thymidine phosphorylase Enzyme Analysis (ENZ06) may also be used for assessment of Variants of Uncertain Significance (VUS) identified during genetic testing (e.g. Next Generation Sequencing or Capillary Sequencing testing). MNGIE is an autosomal recessive disorder caused by mutations in the gene encoding thymidine phosphorylase (TP). The disease is characterized clinically by impaired eye movements, gastrointestinal dysmotility, cachexia, peripheral neuropathy, myopathy and leukoencephalopathy. Molecular genetic studies of MNGIE patients\tissues have revealed multiple deletions, depletion, and site-specific point mutations of mitochrondrial DNA. TP is a cytosolic enzyme required for nucleoside homeostatis. In MNGIE, TP activity is severely reduced and consequently levels of thymidine and deoxyuridine in plasma are dramatically elevated. MNGIE patients may benefit from hematopoietic stem cell transplantation.
Special Instructions
This assay currently is not available in New York state.
Limitations
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Plasma, frozen
Volume
1.0 mL
Minimum Volume
0.5 mL
Container
Sterile screw capped vial
Collection Instructions
Collect 2-4 mL blood in sodium heparin (green-top), EDTA (purple-top) tube, or ACD (yellow-top) tube. Remove plasma and freeze at -20°C.
Stability Requirements
Temperature | Period |
---|---|
Room temperature | Unstable |
Refrigerated | 24 hours |
Frozen | Indefinitely |
Freeze/thaw cycles | None |
Storage Instructions
Store frozen at -20°C and ship frozen.
Causes for Rejection
Thawed sample
LOINC® Map
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
620173 | Thymidine/Deoxyuridine Plasma | 79665-6 | 620168 | Thymidine Result | 48162-2 | |
620173 | Thymidine/Deoxyuridine Plasma | 79665-6 | 620188 | Deoxyuridine Result | 47957-6 | |
620173 | Thymidine/Deoxyuridine Plasma | 79665-6 | 620169 | Interpretation | N/A | |
620173 | Thymidine/Deoxyuridine Plasma | 79665-6 | 630856 | 80563-0 | ||
Order Code | 620173 | |||||
Order Code Name | Thymidine/Deoxyuridine Plasma | |||||
Order Loinc | 79665-6 | |||||
Result Code | 620168 | |||||
Result Code Name | Thymidine Result | |||||
UofM | ||||||
Result LOINC | 48162-2 | |||||
Order Code | 620173 | |||||
Order Code Name | Thymidine/Deoxyuridine Plasma | |||||
Order Loinc | 79665-6 | |||||
Result Code | 620188 | |||||
Result Code Name | Deoxyuridine Result | |||||
UofM | ||||||
Result LOINC | 47957-6 | |||||
Order Code | 620173 | |||||
Order Code Name | Thymidine/Deoxyuridine Plasma | |||||
Order Loinc | 79665-6 | |||||
Result Code | 620169 | |||||
Result Code Name | Interpretation | |||||
UofM | ||||||
Result LOINC | N/A | |||||
Order Code | 620173 | |||||
Order Code Name | Thymidine/Deoxyuridine Plasma | |||||
Order Loinc | 79665-6 | |||||
Result Code | 630856 | |||||
Result Code Name | ||||||
UofM | ||||||
Result LOINC | 80563-0 |