Test ID: G6PD
Glucose-6-Phosphate Dehydrogenase (G-6-PD), Quantitative, Erythrocytes
NY State Approved 
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Evaluation of individuals with Coombs-negative nonspherocytic hemolytic anemia
Method Name A short description of the method used to perform the test
Kinetic Spectrophotometry (KS)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
G6PD Erythrocytes
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube:
Preferred: Yellow top (ACD solution B)
Acceptable: EDTA
Specimen Volume: 6 mL
Collection Instructions: Do not transfer blood to other containers.
Forms: If not ordering electronically, submit a Hematopathology/Molecular Oncology Request Form (Supply T241) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole blood | Refrigerated | 20 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Hemolytic disease may be associated with deficiency of any 1 of 20 erythrocyte enzymes. The most commonly encountered is a deficiency of glucose-6-phosphate dehydrogenase (G-6-PD).
The G-6-PD locus is on the X chromosome, and thus G-6-PD deficiency is a sex-linked disorder. Affected males (hemizygotes) inherit the abnormal gene from their mothers who are almost always asymptomatic carriers (heterozygotes). More than 300 molecular variants of G-6-PD are known, and the clinical and laboratory features of G-6-PD deficiency vary accordingly. With some variants, there is chronic, life-long hemolysis, but more commonly, the condition is asymptomatic and only results in susceptibility to acute hemolytic episodes which may be triggered by some drugs, ingestion of fava beans, viral, or bacterial infections.
The major G-6-PD variants occur in specific ethnic groups. Thus, knowledge of the ethnic background of the patient is important. G-6-PD deficiency has very high frequency in Southeast Asians and is the most common cause of hemolytic disease of the newborn in Southeast Asian neonates.
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.
8.8-13.4 U/g hemoglobin
Interpretation Provides information to assist in interpretation of the test results
Abnormal values are usually 0% to 20% of normal mean.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
In African Americans with the glucose-6-phosphate dehydrogenase (G-6-PD) A-variant, normal values may be measured for several weeks following hemolysis. This is not the case with other G-6-PD variants that predispose to hemolysis.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Beutler E: Glucose-6-phosphate dehydrogenase deficiency. In Hematology. Fifth Edition. Edited by E Beutler, MA Lichtman, BS Coller, TJ Kipps. New York, McGraw-Hill Book Company, 1995, pp 564-586
Method Description Describes how the test is performed and provides a method-specific reference
Glucose-6-phosphate dehydrogenase (G-6-PD) in a hemolysate catalyzes the oxidation of glucose-6-phosphate to 6-phosphogluconate. Concomitantly, icotinamide adenine dinucleotide phosphate (NADP) is changed to its reduced form (NADPH), a reaction measured spectrophotometrically.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. Third edition. New York, Grune and Stratton, 1984, pp 68-71)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
82955
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| G6PD_ | G-6-PD, QN, RBC | 32546-4 |
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