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HelpTest 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.
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, 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 |
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)
Cautions
Recent transfusion may mask the patient’s intrinsic enzyme activity and cause unreliable results.
Some enzyme deficiency disorders can be masked by reticulocytosis and comparison of activities of other RBC enzyme activities in this panel can be useful.
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