According to abbreviationfinder.org, a glucose-6-phosphate dehydrogenase deficiency is a hereditary deficiency of the enzyme glucose-6-phosphate dehydrogenase, which plays an important role in sugar metabolism. The symptoms of the deficiency are very variable, and in severe cases the red blood cells can be destroyed in the form of haemolysis. The disease can be easily controlled by avoiding certain foods and medications.
What is Glucose-6-Phosphate Dehydrogenase Deficiency?
Glucose-6-phosphate dehydrogenase deficiency indicates a deficiency or incorrect functioning of the enzyme glucose-6-phosphate dehydrogenase. The consequences of this deficiency vary. The symptoms vary from asymptomatic to hemolytic crises. Since the disease is inherited via the X chromosome, women are usually less affected than men. This enzyme deficiency is widespread, mainly in malaria areas.
Hemolytic crises are often triggered by beans (fava beans) and certain drugs such as primaquine, nitrofurantoin or sulfanilamide. Because it is triggered by fava beans, glucose-6-phosphate dehydrogenase deficiency is also known as favism when symptoms are present.
Around 400 million people worldwide are affected by this enzyme defect. Most people, mostly women, do not develop any symptoms at all. As a rule, quality of life and life expectancy are not restricted in the case of a glucose-6-phosphate dehydrogenase deficiency. Only foods and medicines that trigger hemolysis should be avoided in severe forms.
Causes
Glucose-6-phosphate dehydrogenase deficiency is caused by a mutation in the G6PD gene on the X chromosome. This gene is responsible for coding the enzyme glucose-6-phosphate dehydrogenase. The severity of the symptoms depends on the specific mutation and the gender of the person. About 150 mutations of this gene are known to date. The function of the enzyme is not equally restricted with every mutation.
Girls and women have two G6PD alleles. In most cases, the defective gene is passed on heterozygous. So there are still enough healthy G6PD genes from the other parent. The second gene is missing in men, so that the glucose-6-phosphate dehydrogenase deficiency has a greater impact. Furthermore, the present mutation decides on the residual activity of the enzyme.
The enzyme glucose-6-phosphate dehydrogenase plays a crucial role in carbohydrate metabolism. It is responsible for converting the oxidized NADP+ into the reduced NADPH. NADH is in turn a cofactor of the enzyme glutathione reductase. Glutathione reductase reduces the dimeric oxidized glutathione to two monomers of reduced glutathione. In its reduced form, glutathione is a powerful antioxidant and scavenges free radicals.
If there is a lack of reduced glutathione, the capacity to destroy free radicals is often insufficient. This is particularly true when many radical intermediate products are formed through the supply of external substances. For example, fava beans, peas or currants contain certain alkaloids that give rise to radical breakdown products. The same applies to certain medications. If there is too little reduced glutathione, the free radicals are not broken down sufficiently.
Their concentration can rise to such an extent that they destroy the erythrocytes, triggering haemolysis. The lack of reduced glutathione is in turn the result of a lack of NADH. Since the formation of NADH is catalyzed by glucose-6-phosphate dehydrogenase, insufficient activity of this enzyme also leads to insufficient regeneration of NADH from NAD+.
Symptoms, Ailments & Signs
A glucose-6-phosphate dehydrogenase deficiency manifests itself in different ways. In general, three different forms of expression are distinguished. There is a symptom-free form of enzyme deficiency. In these cases there are still enough active enzymes available to compensate for the deficiency.
A second form is acute hemolytic anemia, which is induced by fava beans, sulfonamides, vitamin K, naphthalene, or acetylsalicylic acid. Chronic haemolytic anemia, in which red blood cells permanently die off, is observed most rarely. The formation of new blood cells cannot fully compensate for their breakdown. If the symptoms are severe , chills, fever, weakness, shock, back pain or abdominal pain, among other things, occur.
The urine turns black. Jaundice also occurs. Newborns with glucose-6-phosphate dehydrogenase deficiency may suffer from neonatal jaundice. In rare cases even the kidneys can fail completely. In general, compensatory processes take place in the body, so the hemolytic crisis quickly ends. The prognosis of the disease is good. In rare cases, however, a fatal outcome is also possible.
Diagnosis
To diagnose glucose-6-phosphate dehydrogenase deficiency, the doctor will first take a medical history. Glucose-6-phosphate dehydrogenase deficiency is suspected in certain ethnic groups and in individuals with a history of the disease in their family when symptoms such as anemia, jaundice, and signs of hemolysis occur.
Furthermore, laboratory tests for liver enzymes, reticulocyte count, lactate dehydrogenase, haptoglobin or a direct antiglobin test (Coombs test) are carried out. If the Coombs test excludes an immunological cause for the hemolysis, the suspicion of a glucose-6-phosphate dehydrogenase deficiency is confirmed.
NADH can be determined directly using the so-called Beutler test. If no fluorescence of the blood cells is observed, this means a positive Beutler test. This allows the diagnosis of glucose-6-phosphate dehydrogenase deficiency to be confirmed.
Complications
Glucose-6-phosphate dehydrogenase deficiency does not always lead to complications or symptoms. So the deficiency occurs even when there are active enzymes. However, if this is not the case, the glucose-6-phosphate dehydrogenase deficiency can also lead to the death of the red blood cells. This death has relatively serious consequences and symptoms that are similar to an ordinary febrile illness.
This leads to fever, body aches and chills. The stomach and back can also be affected by pain, so that the patient has a severe limitation in everyday life. The quality of life decreases drastically due to the glucose-6-phosphate dehydrogenase deficiency. In the worst case, kidney failure can result, which can even lead to death.
Babies can also develop jaundice due to the deficiency. If the glucose-6-phosphate dehydrogenase deficiency is triggered by a drug or food, the person affected must stop taking it. In most cases, there are no further complications. A causal treatment is not possible. If the deficiency can be remedied, there will be no reduction in life expectancy.
When should you go to the doctor?
People who have relatives in their family environment who are suffering from a glucose-6-phosphate dehydrogenase deficiency should have a genetic test carried out for clarification. Symptoms such as chills, body aches or fever are cause for concern.
The flu-like symptoms must be controlled by a doctor. If the symptoms persist unabated for several days, a doctor must be consulted. General weakness, pain in the back, or abdominal pain should be evaluated and treated.
Increased tiredness, exhaustion or inner restlessness should be clarified by a doctor. If shock occurs, consult a doctor immediately. In severe cases, an ambulance must be informed. Until it arrives, the instructions of the emergency personnel must be followed. Discolored urine is considered unusual. If it turns black, see a doctor as soon as possible.
A doctor’s visit is also necessary for yellowing of the skin. If kidney problems occur, a visit to a doctor is recommended. If there are functional disorders of the kidneys, pain or a reduction in performance, a doctor is needed. If fluid intake is refused because of the symptoms, a doctor’s visit is necessary, as there is a risk of dehydration. In the event of kidney failure, an ambulance must be called. There is a risk of death for the person concerned.
Treatment & Therapy
There is currently no causal therapy for glucose-6-phosphate dehydrogenase deficiency. A blood transfusion may be necessary in acute hemolytic anemia. Otherwise, therapy consists of avoiding foods and drugs that trigger favism.
These include beans (mainly fava beans), peas, currants, vitamin K, acetylsalicylic acid, sulfonamides, naphthalene and aniline derivatives. If these triggers are avoided, no symptoms appear. Life expectancy is not reduced with a glucose-6-phosphate dehydrogenase deficiency.
Outlook & Forecast
Glucose-6-phosphate dehydrogenase deficiency is a genetic disease. Since human genetics cannot be modified for legal reasons, there is no prospect of a cure for the disorder. Therapy is therefore aimed at relieving the symptoms.
A large number of patients do not experience any impairments despite the diagnosed disease. They experience no abnormalities or complaints in the course of their lives. The prognosis is therefore very favorable for them and treatment is not necessary.
However, the person concerned should undergo regular check-ups so that changes or special features can be reacted to as quickly as possible. Normally, reducing the symptoms that occur as a result of the deficiency symptoms is the focus of medical care.
The prognosis is favorable if the patient adheres to certain guidelines. A well-designed treatment and therapy plan aims to improve health. If the patient adheres to a special diet plan, the symptoms are significantly alleviated. The intake of certain foods should be avoided as a priority.
In particular, beans, peas or currants should be removed from the diet for a good prognosis. If they are consumed, the irregularities increase again in a short time. The diet must be adhered to for life so that the well-being is strengthened and the health of the patient is promoted.
Prevention
Because glucose-6-phosphate dehydrogenase deficiency is hereditary, there is no way to prevent it. Only the symptoms of hemolytic anemia can be prevented by avoiding triggering substances.
Aftercare
Special options for aftercare are usually not possible and not necessary in the case of glucose-6-phosphate dehydrogenase deficiency. The person concerned is primarily dependent on the direct treatment of this complaint in order to prevent further complications. Above all, an early diagnosis has a very positive effect on the further course and can help to alleviate the symptoms.
Life expectancy is often not negatively affected by this disease. In the case of glucose-6-phosphate dehydrogenase deficiency, the patient must take medication and other supplements to relieve the symptoms. Likewise, active ingredients that trigger the symptoms should be avoided as far as possible in order to protect the body. When taking the medication, it is important to ensure that it is taken regularly.
Possible interactions with other medications must also be taken into account, and the doctor can also be asked for advice. The doctor can also provide the sufferer with a nutritional plan to ensure a proper diet.
If the symptoms of glucose-6-phosphate dehydrogenase deficiency are severe, it is better to call an ambulance or go straight to the hospital. Contact with other people affected by glucose-6-phosphate dehydrogenase deficiency can also be useful, as this leads to an exchange of information that can be helpful for everyday life.
You can do that yourself
In most cases, glucose-6-phosphate dehydrogenase deficiency can be treated relatively well by avoiding certain foods. This can limit most of the symptoms, so that direct medical treatment is not always necessary. However, a nutrition plan that can also be created with a nutritionist is always suitable.
In an acute emergency, the glucose-6-phosphate dehydrogenase deficiency is usually compensated for by a blood transfusion. In the further course, the person concerned should avoid beans and peas in his food. Currants or vitamin K also have a negative effect and can promote the disease. The patient should also not take aspirin or aniline derivatives. If these ingredients and foods are avoided, the symptoms of glucose-6-phosphate dehydrogenase deficiency can be completely treated.
In many cases, contact with other patients with the disease has a very positive effect on the further course, which can lead to an exchange of information. With a strict diet, the symptoms do not recur, so that no blood transfusions are necessary. As a rule, doing without the triggering foods does not have a particularly negative effect on the patient’s quality of life.