Glucose-6-phosphate dehydrogenase

Keywords: Glucose-6-phosphate dehydrogenase quantitative, Glucose-6-phosphate dehyrogenase screen, G6PD

Specimen:

5 mL blood in ACD, lithium heparin or EDTA.

Method:

Semi-quantitative fluorescence test and methaemoglobin reduction test; enzyme assay.

Molecular genetics techniques are available - consult pathologist.

Reference Interval:

The G-6-PD assay reference intervals are:

3.0-4.2 IU/1010 red cells (WHO)

4.6-13.5 IU/g Hb.

Newborns and infants may have values that deviate from these values by 150%.

Application:

Investigation of haemolytic anaemia, particularly with features of oxidative haemolysis or clinical history suggestive of G-6-PD deficiency.

The specific enzyme assay confirms deficiency.

Interpretation:

Low levels indicate red cell G-6-PD deficiency.

Levels may be normal in acute haemolytic episodes due to reticulocytosis and, therefore, if deficiency is suspected, repeat G-6-PD testing may be indicated after resolution of haemolytic episode.

Reference:

Beutler E. Blood 1994; 84(11): 3613-3636.

Bain et al. Dacie and Lewis Practical Haematology. 11th Ed. 2012.