Glucose-6-phosphate dehydrogenase (G6PD) deficiency

G6PD is important for red blood cells which carry oxygen throughout your body. It helps protect these cells from harmful substances that build up when you have a fever or infection, take certain medicines or eat certain foods. Red blood cells don’t have a brain, so they need extra protection.

If you have G6PD deficiency, your red blood cells may not be protected properly which can cause them to break down. This reduces the number of whole red blood cells and leads to a ‘haemolytic crisis’. When this happens: 

• Some haemoglobin from the broken red cells is released into the blood. Haemoglobin is the part of the cell that carries oxygen around the body.
• The liver processes haemoglobin, causing your eyes and skin to get a yellow tinge. This is known as jaundice.
• Some haemoglobin passes into pee, making it Coca-Cola coloured. This is known as haemoglobinuria.

As the red cells decrease, you may become anaemic, which can make you look pale. If anaemia is severe, you may be breathless, tired and lifeless. When this happens, and for a few days or weeks afterwards, you will need to take folic acid and iron. These help your bone marrow to make new cells. This process usually stops on its own, and your bone marrow will make new cells. If your haemoglobin levels go very low or if you become unwell, you may need a blood transfusion. 

Newborn babies with G6PD deficiency sometimes have haemolytic crises at birth or soon after, even if they haven’t had an infection or taken any medicine. This is probably due to the stress of childbirth. Newborns might need special treatment for jaundice, such as light therapy (phototherapy) or a blood transfusion. 

G6PD deficiency is inherited, which means that it is passed on at birth from one or both parents, usually the mother. It is found in both males and females but usually affects males more severely. Often when a mother passes it on to her son, she may never have had any symptoms.

G6PD deficiency is also found more commonly in people of Mediterranean, Middle Eastern, Asian and African descent. The severity of deficiency varies among different populations. People of African descent are generally less affected than other groups.

Since it is inherited, people are born with the deficiency and there is no known way to prevent it.

• Infection.
• Medication. There is a list of medicines that can trigger a haemolytic crisis in the Pharmacy Formularies. All doctors, nurses and pharmacists can refer to this when you are given a new medication. There will be similar formularies in other countries. Before starting a new medicine, tell the health professional treating you that you are G6PD deficient. They can then check whether it is safe for you to take it. Avoid using non-licensed medicines, such as Chinese medicines, because they haven’t been tested enough to ensure they’re safe. It is ok to have vaccinations, paracetamol and ibuprofen.
• Chemicals, such as aniline dyes (used in fabric and leather) and naphthalene (mothballs). 
• Foods, such as fava (broad) beans.