Triosephosphate Isomerase Enzyme Activity, Blood
Use
Triosephosphate isomerase converts dihydroxyacetone phosphate to glyceraldehyde 3-phosphate during glycolysis. Clinically significant TPI deficiency is a rare autosomal recessive disorder that presents as a severe multisystem disease with early hemolytic anemia and progressive neurologic impairment. Other features may include motor impairment, diaphragm paralysis, cardiomyopathy, and infection susceptibility. Evaluating individuals with chronic nonspherocytic hemolytic anemia and early onset neurologic impairment can aid genetic counseling for those with triosephosphate isomerase deficiency.
Special Instructions
The test is not orderable individually and must be requested as part of a Hemolytic Anemia Evaluation or RBC Enzyme Evaluation profile. Ensure correct specimen collection to prevent diagnostic confusion. Recent transfusions may affect results.
Limitations
Specimen handling is critical as gross hemolysis or fully clotted samples will be rejected. Test results may be masked by recent transfusion, impacting enzyme activity measurement. Reference values are only established for patients 12 months and older. Only one specimen collection attempt is permissible with a minimum volume requirement of 1 mL.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 44054-5
- 44054-5
Result Turnaround Time
5 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
Not provided
Minimum Volume
1 mL
Container
ACD-B tube
Storage Instructions
Refrigerate specimen immediately after collection. Ensure prompt transport to the testing laboratory within the stability time.
Causes for Rejection
Gross hemolysis, fully clotted
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 20 days |