Test Catalog

Test ID: TPIC    
Triosephosphate Isomerase Enzyme Activity, Blood

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluating individuals with chronic nonspherocytic hemolytic anemia


Evaluating individuals with early onset neurologic impairment


Genetic counseling for families with triosephosphate isomerase (TPI) deficiency

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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 Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Only available as part of a profile. For more information see:

-HAEV1 / Hemolytic Anemia Evaluation, Blood

-EEEV1 / Red Blood Cell (RBC) Enzyme Evaluation, Blood


> or =12 months of age: 1033-1363 U/g Hb

Reference values have not been established for patients who are <12 months of age.

Interpretation Provides information to assist in interpretation of the test results

Clinically significant hemolytic anemias due to triosephosphate isomerase (TPI) deficiency are associated with activity levels less than 30% of mean normal. Heterozygotes usually show approximately 50% of mean normal activity and are clinically unaffected.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Recent transfusion may mask the enzyme activity of the patient and cause unreliable results.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Orosz F, Olah J, Ovadi J: Triosephosphate isomerase deficiency: facts and doubts. IUBMB Life. 2006 Dec;58(12):703-715. doi: 10.1080/15216540601115960

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. doi: 10.1111/j.1600-0609.2010.01451.x

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