Glucose-6 Phosphate Deficiency (G6PD Deficiency) – Living With A Special Diet
You are more likely to develop this condition if you:
- Are African American
- Are of Middle Eastern decent, particularly Kurdish or Sephardic Jewish
- Are male
- Have a family history of the deficiency
- 1 in every 12 Greek Cypriots are G6PD deficient,
- 1 in every 5 Africans are G6PD deficient,
- 1 in every 10 African-Caribbean are G6PD deficient,
- 1 in every 5 Indians are G6PD deficient,
- 1 in every 30 Chinese,
- 1 in every 5 Thais are G6PD deficient.
- It has been suggested that G6PD deficiency offers some protection against malaria.
The deficit is most prevalent in Africa (affecting up to 20% of the population), but is common also around the Mediterranean (4% – 30%) and Southeast Asia. Please note that there are more than 400 genetic variants of the deficiency.
G6PD deficiency is most common in males of African heritage. Many females of African heritage are carriers of G6PD deficiency, meaning they can pass the gene for the deficiency to their children but do not have symptoms; only a few are actually affected by G6PD deficiency.
People of Mediterranean heritage, including those of Italian, Greek, Arabic, and Sephardic Jewish backgrounds, also are commonly affected. The severity of G6PD deficiency varies among these groups — it tends to be milder in those of African heritage and more severe in people of Mediterranean descent.
Why does G6PD deficiency happen more often in certain groups of people? It is known that Africa and the Mediterranean basin are high-risk areas for the infectious disease malaria. Researchers have found evidence that the parasite that causes this disease does not survive well in G6PD-deficient cells. So they believe that the deficiency may have developed as a protection against malaria.
The frequency quoted in Pakistan is between 3-6.9% along with Southern China and Southern Russia i.e the areas adjoining Pakistan. This study shows the frequency to be 4.5% which is in conformity with the W.H.O data (Mehmood, A., & Akhtar, M. 2010).
What is G6PD?
When the condition is identified through newborn screening and properly managed, children with G6PD deficiency often can lead healthy lives. Rarely, kidney failure or death may occur following a severe hemolytic event.
Classes of G6PD Enzyme Variants
|CLASS||LEVEL OF DEFICIENCY||ENZYME ACTIVITY||PREVALENCE|
|I||Severe||Chronic nonspherocytic hemolytic anemia in the presence of normal erythrocyte function||Uncommon; occurs across populations|
|II||Severe||Less than 10 percent of normal||Varies; more common in Asian and Mediterranean populations|
|III||Moderate||10 to 60 percent of normal||10 percent of black males in the United States|
|IV||Mild to none||60 to 150 percent of normal||Rare|
|V||None||Greater than 150 percent of normal||Rare|
Comparison of the Two Most Common Variants of G6PD Deficiency
|G6PD MEDITERRANEAN||G6PD A–|
|World Health Organization class||Class II||Class III|
|Populations affected||Italian, Grecian, Spanish, Arabic, Jewish (Kurdish) descent||African descent|
|Neonatal hyperbilirubinemia||Yes, may be more severe||Yes|
|Favism||More common||Less common|
|Hemolysis with oxidative drugs||Yes||Yes|
G6PD is one of many enzymes that help the body process carbohydrates and turn them into energy. G6PD also protects red blood cells from potentially harmful byproducts that can accumulate when a person takes certain medications or when the body is fighting an infection.
In people with G6PD deficiency, either the RBCs do not make enough G6PD or what is produced cannot properly function. Without enough G6PD to protect them, RBCs can be damaged or destroyed. Hemolytic anemia occurs when the bone marrow (the soft, spongy part of the bone that produces new blood cells) cannot compensate for this destruction by increasing its production of RBCs.
G6PD deficiency is an inherited condition in which the body doesn’t have enough of the enzyme glucose-6-phosphate dehydrogenase, or G6PD, which helps red blood cells (RBCs) function normally. This deficiency can cause hemolytic anemia, usually after exposure to certain medications, foods, or even infections.
Most people with G6PD deficiency don’t have any symptoms, while others develop symptoms of anemia only after RBCs have been destroyed, a condition called hemolysis. In these cases, the symptoms disappear once the cause, or trigger, is removed. In rare cases, G6PD deficiency leads to chronic anemia.
G6PD deficiency is passed along in genes from one or both parents to a child. The gene responsible for this deficiency is on the X chromosome.
A child with G6PD deficiency who is exposed to a medication or infection that triggers the destruction of RBCs may have no symptoms at all. In more serious cases, a child may exhibit symptoms of hemolytic anemia (also known as a hemolytic crisis), including:
- paleness (in darker-skinned kids, paleness is sometimes best seen in the mouth, especially on the lips or tongue)
- extreme tiredness
- rapid heartbeat
- rapid breathing or shortness of breath
- jaundice, or yellowing of the skin and eyes, particularly in newborns
- an enlarged spleen
- dark, tea-colored urine
- Sudden rise of body temperature
Once the trigger is removed or resolved, the symptoms of G6PD deficiency usually disappear fairly quickly, typically within a few weeks.
Symptoms and Laboratory Evaluation in Patients with G6PD and Acute Hemolysis
|SYMPTOMS||LABORATORY EVALUATION||FINDINGS IN PATIENTS WITH G6PD DEFICIENCY AND ASSOCIATED ACUTE HEMOLYSIS|
|Back pain||Complete blood count||Mild to severe anemia|
|Abdominal pain||Reticulocyte count||Increases four to seven days after hemolysis|
|Jaundice||Peripheral blood smear||Heinz bodies|
|Hemoglobinuria||Liver function tests||Elevated indirect bilirubin|
|Scleral icterus||Coombs’ test||Negative|
What to Do in Case Of Hemolytic Crisis
Upon detecting the symptoms listed above,
- You should either call your physician or pediatrician, or go directly to the nearest hospital. Avoid the intake of any drugs.
- You would most probably be requested to list all foodstuffs and drugs taken in the preceding 48 hours, so try to recall and list them.
SORT: KEY RECOMMENDATIONS FOR PRACTICE
|CLINICAL RECOMMENDATION||EVIDENCE RATING||REFERENCES|
|Patients with G6PD deficiency should avoid exposure to oxidative drugs (Table 3) and ingestion of fava beans.||C||3|
|Neonates should be screened for G6PD deficiency when family history, ethnic or geographic origin, or the timing of the appearance of neonatal jaundice suggests the possibility of G6PD deficiency.||C||23|
|G6PD can be diagnosed with a quantitative spectrophotometric analysis or, more commonly, by a rapid fluorescent spot test.||C||7|
G6PD = glucose-6-phosphate dehydrogenase.
A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, see page 1154 orhttps://www.aafp.org/afpsort.xml.
Other tests that may be done include:
- Bilirubin level
- Complete blood count, including red blood cell count
- Hemoglobin – blood
- Hemoglobin – urine
- Haptoglobin level
- LDH test
- Methemoglobin reduction test
- Reticulocyte count
The best way to care for a child with G6PD deficiency is to limit exposure to the triggers of its symptoms. With the proper precautions, G6PD deficiency should not keep your child from living a healthy, active life.
If symptoms are mild, no medical treatment is usually needed. As the body naturally makes new red blood cells, the anemia will improve. If symptoms are more severe, a child may need to be hospitalized for supportive medical care.
The main treatment for G6PD deficiency is avoidance of oxidative stressors. Rarely, anemia may be severe enough to warrant a blood transfusion. Splenectomy generally is not recommended. Folic acid and iron potentially are useful in hemolysis, although G6PD deficiency usually is asymptomatic and the associated hemolysis usually is short-lived. Antioxidants such as vitamin E and selenium have no proven benefit for the treatment of G6PD deficiency. Research is being done to identify medications that may inhibit oxidative-induced hemolysis of G6PD-deficient red blood cells.
Medications That Should Be Avoided By Persons with G6PD Deficiency*
|Dapsone||Antimicrobial for treatment of leprosy|
|Flutamide (Eulexin)||Antiandrogen for treatment of prostate cancer|
|Mafenide cream (Sulfamylon)||Topical antimicrobial|
|Methylene blue (Urolene Blue)||Antidote for druginduced methemoglobinemia|
|Nalidixic acid (NegGram)||Antibiotic used primarily for urinary tract infections|
|Nitrofurantoin (Macrodantin)||Antibiotic used primarily for urinary tract infections|
|Phenazopyridine (Pyridium)||Analgesic for treatment of dysuria|
|Rasburicase (Elitek)||Adjunct to antineoplastic agents|
|Sulfacetamide (Klaron)||Antibiotic (ophthalmic and topical preparations)|
|Sulfamethoxazole (Gantanol)||Antibiotic used in combination preparations (i.e., trimethoprim-sulfamethoxazole [TMP-SMX; Bactrim, Septra])|
|Sulfanilamide (AVC)||Antifungal agent for treatment of vulvovaginalCandida albicansinfection|
- Allowed: Consume fats from natural fat sources such as coconut oil, olive oil, palm oil or animal fat. Obtain your vitamins and minerals from natural sources such as bone stock soups. Round out your diet with proteins and carbohydrates not found on the G6PD Deficiency forbidden foods list.
- Forbidden: The G6PD Deficiency website lists several foods that you should not eat at any time. Do not consume foods or supplements that contain large amounts of VItamin C, also called ascorbic acid, or artificial blue dyes. Do not eat menthol, or menthol-containing foods such as breath mints or candy. Do not eat legumes, such as lima beans, fava beans, kidney beans or soybeans. Avoid any soy-containing products, such as tofu, bean curds, miso or textured soy protein. Look out for less easily recognizable legumes such as alfalfa sprouts, peanuts, licorice or carob. Some legumes — such as fava beans — cause severe hemolysis — but several other legumes, beans and pulses cause less severe hemolysis that, while mild enough to evade initial detection, can still damage your health.
- Avoidance: Avoid already-prepared Chinese foods. These foods can contain herbs that could provoke a hemolytic episode. These herbs include Flos Chimonanthi praecosis, Rhizoma coptidis, margarita, Flos ionicerae and Calculus bovis. Furthermore, avoid packaged foods that might contain forbidden food ingredients. These foods include margarine, jarred salad dressings, canned soups, potato chips, canned fish and meats, hot dogs, sausages, processed meats, lowfat cheeses and sauces such as sweet and sour sauce or Worcestershire sauce.
- Warning: Ask your doctor for an updated G6PD deficiency forbidden foods list every six months to ensure that you do not continue to eat foods shown to initiate hemolytic episodes. Your doctor might also suggest that you hire a registered dietitian familiar with this disorder to better ensure that your nutritional needs are met in relation to your other current medical conditions.
The best therapy is simply to avoid the prohibited drugs and foodstuffs. In case of a hemolytic crisis, the most effective therapy is blood transfusion. In milder cases of the deficiency, transfusion is usually not required. But in others where the rate of hemolysis is very rapid (as in all persons suffering from Favism), “transfusions of whole blood or packed cells may be useful” (Ernest Beutler, MD). In areas where G-6-PD deficiency is common, care must be taken to avoid giving G-6-PD deficient blood to the patient.
Advice for Parents
Any boy suffering from it should be informed of his deficiency so he can help himself avoid the intake of the forbidden foodstuff in various situations where he is not under your supervision (such as school). You should also inform school supervisors and, where applicable, also the school caterers who provide school lunch. Best is to carry with you the ‘avoid list’ and show it to all those who may treat your boy.