What is G6PD Deficiency?
G6PD Deficiency or Glucose-6-phosphate dehydrogenase deficiency is a genetic disorder that primarily affects the red blood cells which are responsible for transporting oxygen from the lungs to tissues present all over the body. G6PD Deficiency commonly affects males more than females. There is a defect in glucose-6-phosphate dehydrogenase (which is an enzyme) resulting in premature breakdown of red blood cells (hemolysis). Glucose-6-phosphate dehydrogenase deficiency is also known as G6PDD and deficiency of glucose-6-phosphate dehydrogenase.
Hemolytic anemia is the most common medical condition which occurs with G6PD Deficiency or glucose-6-phosphate dehydrogenase deficiency, as the speed of destruction of the red blood cells is faster than their replacement by the body. Due to hemolytic anemia, patient experiences symptoms, such as paleness, fatigue, jaundice, rapid heart rate, dark urine and breathlessness. Hemolytic anemia in patients suffering from G6PD Deficiency or glucose-6-phosphate dehydrogenase deficiency is commonly triggered by viral/bacterial infections or due to some type of medicines, such as medications for treating malaria and some specific antibiotics. Hemolytic anemia can develop in some people after inhalation of pollen from fava plants (favism) or after consuming fava beans. G6PD Deficiency is also one of the main causes of mild to severe jaundice in newborn babies. However, most of the patients who have this disorder do not have any symptoms.
Treatment for G6PD Deficiency or Glucose-6-dehydrogenase deficiency comprises of removing the trigger factor and in serious cases, hospitalization may be needed.
Causes & Epidemiology of G6PD Deficiency
G6PD Deficiency or Glucose-6-phosphate dehydrogenase deficiency is caused by mutations in the G6PD gene. The function of G6PD gene is providing instructions for making glucose-6-phosphate dehydrogenase, which is an enzyme that is used for processing carbohydrates. This enzyme also helps in protecting the red blood cells from the effects of reactive oxygen species. Any type of chemical reaction that involves glucose-6-phosphate dehydrogenase causes production of compounds, which will inhibit building up of the reactive oxygen species to toxic levels within the red blood cells.
If there are any mutations in the G6PD gene, then it changes the structure of the enzyme or decreases its production, due to which this enzyme will not be able to play its protective role. This results in accumulation of reactive oxygen species and damage or destruction of the red blood cells. Certain factors, such as or ingesting fava beans, certain drugs and infections can also lead to increase in the levels of reactive oxygen species, which results in faster destruction of the red blood cells before they can be replaced by the body. Decrease in the red blood cells leads to hemolytic anemia.
G6PD deficiency is a genetic disorder and is passed to the patient through genes from either one or both the parents. X chromosome carries this gene. G6PD Deficiency is more commonly found in certain parts of Asia, Africa and the Mediterranean. Males of African heritage more commonly have G6PD deficiency. About 1 in 10 African-American males are affected with G6PD Deficiency in the United States. Many females who are of African heritage are carriers of G6PD deficiency, i.e. this gene can be passed to their children through them, but they do not experience any symptoms.
Other than this, individuals of Mediterranean heritage, including Greek, Italian, Sephardic Jewish and Arabic backgrounds are also commonly affected with G6PD deficiency. The severity of G6PD deficiency differs in these groups. It tends to be more severe in people of Mediterranean descent and milder in individuals of African heritage.
Triggers of G6PD Deficiency
Children having G6PD deficiency usually will not exhibit any symptoms of this condition till their RBCs are exposed to certain triggers, such as:
- Certain fever-reducing medicines and painkillers.
- Bacterial and viral infections.
- Certain medicines for treating malaria particularly which have "quine" in their names.
- Certain type of antibiotics, particularly those that have "sulf" in their names.
Some percentage of children who have G6PD deficiency are able to tolerate the medications in small dosages; whereas, some children will not be able to take them at all. It is important to consult your doctor for a complete list of medications, which can cause problems in children with G6PD deficiency.
In some children with G6PD deficiency, certain substances can cause harm when they are consumed or touched, e.g. naphthalene and fava beans. Such types of things which worsen the child’s condition should be strictly avoided and should be kept out of touch of the child so that he/she does not touch or swallow them.
Signs & Symptoms of G6PD Deficiency
Children having G6PD deficiency and who have had an infection or have been exposed to certain medication which triggers hemolysis (destruction of RBCs) may be asymptomatic. In severe cases, patient may have symptoms of hemolytic anemia such as:
- Extreme tiredness.
- Paleness is seen in darker-skinned kids, especially in the mouth, tongue or lips.
- Shortness of breath or rapid breathing.
- Weak and rapid pulse rate.
- Yellowing of the skin and eyes (jaundice), especially in newborns.
- Spleen enlargement.
- Dark or yellow-orange colored urine.
- Abrupt increase in the temperature of the body.
Diagnosis of G6PD Deficiency
In many patients, G6PD deficiency remains undiagnosed until the patient starts to experience symptoms. Blood tests are done to confirm the diagnosis of G6PD deficiency and also to exclude other causes of anemia. Screening with blood tests can be done if the child or patient is at risk to develop G6PD deficiency because of ethnic background or family history.
Treatment of G6PD Deficiency
The symptoms of G6PD deficiency commonly will resolve in a few weeks after the trigger factor has been eliminated. Treatment of symptoms of G6PD deficiency is simple, as once the trigger for the symptoms is removed, such as stopping the use of a certain medicine or treating the infection/illness etc., the symptoms of G6PD deficiency will resolve. No treatment is needed for mild symptoms. The human body continuously produces new red blood cells, so the anemia will gradually improve. For severe symptoms/anemia, the patient may need hospitalization for supportive treatment, such as I.V. fluids, oxygen and blood transfusion (if needed). Rarely, this deficiency can lead to some other type of serious medical problem.
Important Facts (Brief Summary) about G6PD Deficiency
- G6PD Deficiency or Glucose-6-phosphate dehydrogenase deficiency is a genetic disorder where there is a defect in an enzyme known as glucose-6-phosphate dehydrogenase that causes premature breakdown of the red blood cells (hemolysis).
- This leads to hemolytic anemia, which produces symptoms, such as jaundice, paleness, fatigue, dark urine, rapid heart rate and shortness of breath.
- Trigger factors consist of certain drugs, infections or consumption of fava beans which elevates the levels of reactive oxygen species resulting in rapid destruction of the red blood cells before they can be replaced by the body. Decrease in the amount of red blood cells leads to signs and symptoms of hemolytic anemia.
- The X chromosome carries the G6PD Deficiency or glucose-6-phosphate dehydrogenase deficiency.
- Men are more affected by this disorder than women.
- Treatment is not required for mild symptoms and removing the trigger will resolve the symptoms. For severe symptoms, hospitalization may be required.