Test Code 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.
Method Name
Kinetic Spectrophotometry (KS)
Specimen Type
Whole Blood ACD-BSpecimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Whole Blood ACD-B | Refrigerated | 20 days |
Reject Due To
Gross hemolysis | Reject |
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.
Performing Laboratory

CPT Code Information
82657
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.