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Test Code PGK1 Phosphoglycerate Kinase Enzyme Activity, Blood


Specimen Required


Container/Tube:

Preferred: Yellow top (ACD solution B)

Acceptable: Lavender top (EDTA)

Specimen Volume: 6 mL

Collection Instructions: Send specimen in original tube. Do not transfer blood to other containers.


Secondary ID

607457

Useful For

Evaluation of individuals with Coombs-negative nonspherocytic hemolytic anemia, especially if X-linked inheritance pattern

 

Evaluation of individuals with myopathic or neurologic symptoms

Method Name

Kinetic Spectrophotometry

Reporting Name

Phosphoglycerate Kinase, 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

Reject Due To

Gross hemolysis Reject
Fully clotted Reject

Clinical Information

Phosphoglycerate kinase (PGK) is an enzyme that converts 1,3-diphosphoglycerate (1,3-DPG) to 3-phosphoglyceric acid (3-PGA) in one of the adenosine triphosphate (ATP) generating steps in glycolysis. PGK deficiency (OMIM # 300653) is an X-linked disorder with a variable clinical phenotype. Manifestations include hemolytic anemia, myopathy/rhabdomyolysis, or neurologic impairment. Patients can have 1 or 2 systems affected, but rarely have all 3. Clinical severity may not correlate with enzyme activity, and female heterozygotes may be mildly affected.

Reference Values

≥12 months: 142-232 U/g Hb

Reference values have not been established for patients who are less than12 months of age.

Interpretation

In phosphoglycerate kinase (PGK) deficiency, RBC activity levels have been reported ranging from 1% to 49% of mean normal; however, affected patients more typically have values below 20% of normal mean. (1)

Method Description

Phosphoglycerate kinase (PGK) catalyzes the phosphorylation of adenosine diphosphate (ADP) to adenosine triphosphate (ATP) by conversion of 1,3-diphosphoglycerate (1,3-DPG) to 3-phosphoglyceric acid (3-PGA). In this assay, the reaction is driven in the reverse direction. The formation of 1,3-DPG is then measured through the glyceraldehyde phosphate dehydrogenase (GAPD) reaction as 1,3-DPG is converted to glyceraldehyde-3-phosphate (GAP) resulting in the oxidation of reduced nicotinamide adenine dinucleotide (NADH) to NAD(+). The decrease in absorbance which occurs as NADH is oxidized is measured spectrophotometrically at 340 nm on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984:40-42; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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
PGK1 Phosphoglycerate Kinase, B 44053-7

 

Result ID Test Result Name Result LOINC Value
PGKCL Phosphoglycerate Kinase, B 44053-7

Day(s) Performed

Tuesday, Thursday

Forms

If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen.