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HelpTest ID: TPI1 Triosephosphate Isomerase Enzyme Activity, Blood
Specimen Required
Container/Tube:
Preferred: Yellow top (ACD solution B)
Acceptable: Lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions: Send in original tube. Do not transfer blood to other containers.
Useful For
Evaluating individuals with chronic nonspherocytic hemolytic anemia
Evaluating individuals with early onset neurologic impairment
Genetic counseling for families with triosephosphate isomerase deficiency
Method Name
Kinetic Spectrophotometry (KS)
Reporting Name
Triosephosphate Isomerase, BSpecimen Type
Whole Blood ACD-BSpecimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood ACD-B | Refrigerated | 20 days |
Clinical Information
Triosephosphate isomerase (TPI) converts dihydroxyacetone phosphate to glyceraldehyde 3-phosphate during glycolysis. Clinically significant TPI deficiency (OMIM #615512, autosomal recessive) is rare and classically manifests as a severe multisystem disorder with early hemolytic anemia and progressive neurologic impairment in infancy. Other clinical features include motor impairment, diaphragm paralysis, cardiomyopathy, and susceptibility to infections. Some cases have isolated hemolytic anemia.
Reference Values
≥12 months: 1033-1363 U/g Hb
Reference values have not been established for patients who are less than12 months of age.
Interpretation
Clinically significant hemolytic anemias due to triosephosphate isomerase deficiency are associated with activity levels below 30% of mean normal. Heterozygotes usually show approximately 50% of mean normal activity and are clinically unaffected.
Clinical Reference
1. Orosz F, Olah J, Ovadi J. Triosephosphate isomerase deficiency: facts and doubts. IUBMB Life. 2006;58(12):703-715
2. Fermo E, Bianchi P, Vercellati C, et al. Triose phosphate isomerase deficiency associated with two novel mutations in TPI gene. Eur J Haematol. 2010;85(2):170-173
3. Tanaka KR, Zerez CR. Red cell enzymopathies of the glycolytic pathway. Semin Hematol. 1990;27:165-185
4. Koralkova P, van Solinge WW, van Wijk R. Rare hereditary red blood cell enzymopathies associated with hemolytic anemia-pathophysiology, clinical aspects, and laboratory diagnosis. Int J Lab Hematol. 2014;36:388-397
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
82657
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TPI1 | Triosephosphate Isomerase, B | 44054-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TPICL | Triosephosphate Isomerase, B | 44054-5 |
Day(s) Performed
Tuesday, Thursday
Report Available
1 to 6 daysForms
If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen.
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