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Test ID: TPI1 Triosephosphate Isomerase Enzyme Activity, Blood

Specimen Required


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, B

Specimen Type

Whole Blood ACD-B

Specimen 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 (DHAP) to glyceraldehyde 3-phosphate (G3P) 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.


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 Dec;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 Aug;85(2):170-173

3. Tanaka KR, Zerez CR: Red cell enzymopathies of the glycolytic pathway. Semin Hematol. 1990;27:165

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. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


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
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