G6PD deficiency

What is G6PD?

G6PD is short for glucose 6 Phosphate Dehydrogenase. It is an enzyme which is found throughout the body. Some people have an inherited deficiency of G6PD, which results in low levels of the enzyme in the red blood cells, and this may cause occasional problems for them. Certain drugs, viruses and food substances cause the problem which breakdown G6PD deficient red cells and cause anaemia.

How is it inherited?

Both males and females inherit G6PD deficiency but males are more severely affected. Individuals at greatest risk of inheriting it are those who’s family originate from the Mediterranean, Asia, Africa, Caribbean and South East Asia. For example G6PD deficiency is found in:

• 1 in 12 Cypriots
• 1 in 5 Africans
• 1 in 10 Afro Caribbeans
• 1 in 5 Indians
• 1 in 30 Chinese
• 1 in 5 Thais

There are many different kinds of G6PD deficiency, but the kinds found in people from the Mediterranean and South East Asia are usually more severe than those in other groups.

When can G6PD cause anaemia?

People with G6PD deficiency are usually completely healthy until exposed to certain drugs, foods and infections. These are listed in the ‘Items to avoid’ section and exposure to them results in a breakdown of red blood cells and anaemia (low concentration of haemoglobin). Fava beans (broad beans) and drugs used to prevent and treat malaria are to be strictly avoided as are the medications listed in the ‘Items to avoid’ section.

Some people have a severe form of the condition with breakdown of red cells even without exposure to the above triggers. These patients are said to have chronic non-spherocytic haemolytic anaemia. They sometimes require blood transfusions. Whatever the severity of G6PD deficiency, all patients are at risk of crises when their haemoglobin drops to dangerously low levels due to a viral infection that stops the bone marrow from producing red cells (aplastic crisis). Aplastic crisis is dangerous and you should contact us immediately in the event of sudden tiredness with a pale appearance. Most crisis will require transfusion of blood to correct the severe anaemia.

Problems for an unborn child

G6PD deficiency does not cause problems for an unborn child.

Jaundice in a new-born baby

Mild jaundice (increase in a blood pigment called bilirubin) is common at birth due to immaturity of the liver. G6PD deficiency increases the risk of severe jaundice in the first few days after birth and this can result in damage to the brain if not detected and treated in time. When you become pregnant, alert the midwife and doctor in charge of the antenatal care to this risk as they may wish to make special arrangements to monitor the newborn.

When should you seek medical advice?

If you become unwell with pale and yellow looking skin, backache and dark urine you should either contact us directly 0114 271 7000 (ask for Haematology) or go to your GP or nearest Emergency Department and present this information resource.