G6PD Test

A healthcare provider orders this test if he/she suspects a G6PD deficiency in a person. It means there is not enough G6PD activity in the body. A G6PD deficiency can increase the rate of haemolysis in the body. It is known as a haemolytic episode.

A haemolytic episode can be caused by certain foods, medicines or infections including:

• Drugs used to reduce fever
• Nitrofurantoin
• Phenacetin
• Primaquine
• Sulphonamides
• Thiazide diuretics
• Tolbutamide
• Quinidine

Some signs and symptoms of RBC destruction include:

• Fatigue
• Weakness
• Pallor (pale skin)
• Rapid heart rate
• Shortness of breath
• Fainting
• Jaundice
• Red/brown-coloured urine
• Enlarged spleen

This test is also recommended if other causes of anaemia and jaundice are negated.

No special preparation is needed for this test. However, you should inform your healthcare provider about your current medications (including prescriptions and nutritional supplements), as certain drugs can alter the results of this test.

Do not undergo this test after a blood transfusion, as it can also affect results.

Do inform your doctor if you have taken any sulfa medicines recently, such as antibacterial or antifungal drugs, anticonvulsants and diuretics or water pills. Adverse reactions are caused by sulfa drugs.

Fasting before the test is not required.

A lab. technician will clean the site of blood collection, ie, your arm and insert a needle into a vein to draw a blood sample.

Later, the collected blood is sent to the laboratory for further analysis.

Some people feel lightheaded after the test or notice a bruise at the injection site, though both these symptoms fade away on their own.

Test results may vary according to the age, gender, the method use or health history. You'll have to ask your healthcare provider for the correct interpretation of the results.

Normal results: The normal range for G6PD is 5.5-20.5 units/gram of haemoglobin. Any value within this range indicates that there is no G6PD deficiency in blood cells.

Abnormal results: It is an indicator of G6PD deficiency. A level less than 10% of the normal range signifies severe deficiency and chronic haemolytic anaemia.

Moderate deficiency can be seen with levels 10-60% less than the normal range. It can be due to the presence of intermittent haemolytic anaemia, which is caused due to certain infections or medications.

Women who are carriers (having a normal gene and a mutated gene) have two forms of RBCs: one with G6PD deficiency and the other with no G6PD deficiency. These women will rarely experience any symptom. However, they will have significantly low G6PD levels, which may not be identified through a G6PD screen test but through a G6PD confirmation test.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.