G6PD (glucose-6-phosphate dehydrogenase) is an enzyme involved in energy production within the cells of the body, and protection of our cells (particularly red blood cells, RBCs) from damage during oxygenation. In some individuals, this enzyme is found to be deficient in levels. If RBCs in the blood cannot be protected from oxidative damage by any other means, they are vulnerable to getting damaged in G6PD deficiency. On exposure to chemicals or triggers, RBCs break down occurs leading to haemolytic anaemia.
The most common enzyme deficiency in humans, G6PD deficiency is particularly prevalent in certain areas such as Sub-Saharan Africa, the Middle East, and Southeast Asia. It is an inherited disease, and because it is linked to the X-chromosome (and men have only one of these in their genetic structure), it is more common in men than women.
Why Should We Screen For G6PD Deficiency?
G6PD deficiency is usually not a problem until the sufferer is exposed to certain triggers, causing acute haemolytic episodes potentially leading to chronic anaemia, kidney and/or liver failure, and in rare cases, death. To avoid these complications, it is important to screen for this disease and if present, avoid the triggers. Being aware of the condition can allow the individual to take the necessary precautions and live a healthy, active life.
Universal screening for G6PD deficiency in newborns is performed in many industrialised nations as G6PD deficiency is a major cause of neonatal jaundice that can lead to complications. Neonatal screening, followed by parent counselling and education can lead to a decrease in the development of the life-threatening complications of the condition.
Who Should Be Screened?
Ongoing research about the benefits of universal screening vs. screening those at higher risk. In countries where there is a high prevalence of the condition, universal neonatal screening is carried out within 48 hours of birth.
Other regions test neonates who develop unexplained persistent jaundice. If left undiagnosed, development of kernicterus might lead to complications and even death.
In adults, anyone with haemolytic anaemia should be tested for G6PD deficiency, especially if anemia is caused by an acute trigger. Signs and symptoms suggestive of haemolytic anaemia include:
- Weakness and tiredness
- Pallor (pale skin)
- Shortness of breath on minimal exertion
- Increased heart rate
- Enlarged spleen
- Dark-coloured urine
How is G6PD Screening Done?
The screening test is carried out on a blood sample collected from a vein in the arm of adults, or by heel prick in babies. The test requires no special preparation. However, it should be postponed in event of a recent haemolytic episode or recent blood transfusion (used to treat your anaemia).
What to Do in Case of a Positive Screening Test
If the results of screening test suggest that you have G6PD deficiency, your doctor may order a quantitative test of G6PD to see how severe the deficiency is.
G6PD deficiency can be managed by prevention. Avoidance of triggering agents allows sufferers to live a healthy life. Talk to your doctor about it, but common triggers are:
- Drugs such as chloroquine, primaquine, aspirin, NSAIDs (non-steroidal anti-inflammatories), dapsone, sulfonamides, ciprofloxacin, nitrofurantoin, etc.
- Exposure to naphthalene (moth balls)
- Food such as fava beans, blueberries, and soy products
- Exposure to henna (black or red Egyptian type) used in tattoos and dyes
- Acute bacterial and viral infections
See your doctor if you experience these symptoms. Prompt diagnosis and treatment is key during a haemolytic episode.
An important element of living with G6PD deficiency is genetic counselling. It helps in understanding the inheritance patterns, risks, and implications to your children.
Living with G6PD deficiency does not have to be a burden. In this condition where most people are asymptomatic, knowing that you have the condition is half the battle won. In case you think you might need G6PD screening, contact your health provider today, and take a step towards a healthier and safer future.
If you’re interested in learning more about G6PD deficiency and the benefits of screening, read on more about it in our biomarker post here!