G6PD deficiency
An inherited enzyme shortage that leaves red blood cells vulnerable to certain triggers — some medicines, infections and foods (notably fava beans). When triggered, red cells break down suddenly, causing an episode of anaemia and jaundice; between episodes people are usually well.
What it is
Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that helps protect red blood cells from oxidative stress — a kind of chemical damage. In G6PD deficiency, an inherited condition, this protection is reduced, so red cells are vulnerable when they meet certain 'oxidative' triggers. The triggers include some medicines (such as certain antibiotics, antimalarials and other drugs), infections, and specific foods — most famously fava (broad) beans, which is why one form is called favism. When a person with G6PD deficiency is exposed to a trigger, a batch of red cells can break down suddenly (acute haemolysis), causing a temporary anaemia with tiredness, pallor, jaundice and dark urine, coming on hours to a couple of days after exposure. Between triggers, most people have no symptoms and a normal blood count; the condition is often lifelong and quiet, punctuated by these episodes. It is one of the most common inherited enzyme conditions worldwide and is most frequent in people of African, Mediterranean, Middle Eastern and Asian origin. It mostly affects males, because the gene is on the X chromosome. Diagnosis is by measuring the G6PD enzyme level in the blood (ideally not during an acute episode, when it can read falsely normal). The mainstay of care is knowing and avoiding one's triggers.
Key lab markers
- G6PD enzyme level — the diagnostic test; low confirms the deficiency (best measured when not acutely haemolysing).
- Full blood count — normal between episodes; anaemia during a haemolytic episode.
- Reticulocytes — rise as the marrow responds to an episode.
- Bilirubin and LDH — raised, and haptoglobin low, during haemolysis.
- Urine — may be dark during an acute episode.
Symptoms
- Usually none between triggers
- During a triggered episode: sudden tiredness and pallor, jaundice (yellow skin/eyes), dark urine
- Sometimes a fast heartbeat or breathlessness if the anaemia is marked
- In newborns, it can contribute to jaundice
Related lab panels
When to discuss with a doctor
The key to living with G6PD deficiency is knowing your triggers and avoiding them — your doctor or pharmacist can provide a list of medicines and foods (including fava beans) to avoid, and it is important to mention the condition before any new medicine is prescribed. A triggered haemolytic episode — sudden pallor, jaundice, dark urine, and feeling unwell after a new medicine, an infection or eating fava beans — needs prompt medical assessment, and a severe episode can require urgent care. In newborns, G6PD deficiency can worsen jaundice and is watched for. Because the enzyme test can read falsely normal during an acute episode, timing matters, and diagnosis is confirmed by a doctor. Mediora.AI can flag the acute haemolysis pattern (anaemia with a high reticulocyte count, raised bilirubin and LDH, low haptoglobin) and a low G6PD level, but diagnosis, trigger avoidance and care belong with your doctor.