Deficiência de G6PD é uma condição hereditária em que o corpo não tem o suficiente da enzima glicose-6-fosfato desidrogenase, ou G6PD, o que ajuda as células vermelhas do sangue (hemácias) funcionam normalmente. This deficiency can cause hemolytic anemia , usually after exposure to certain medications, foods, or even infections. Esta deficiência pode causar anemia hemolítica, geralmente após a exposição a certos medicamentos, alimentos, ou até mesmo infecções.

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 . A maioria das pessoas com deficiência de G6PD não tem nenhum sintoma, enquanto outros desenvolvem sintomas de anemia só depois de hemácias foram destruídas, uma condição chamada hemólise. In these cases, the symptoms disappear once the cause, or trigger, is removed. Nestes casos, os sintomas desaparecem quando a causa, ou gatilho, é removido. In rare cases, G6PD deficiency leads to chronic anemia . Em casos raros, a deficiência de G6PD leva a crônica anemia .

With the right precautions, a child with G6PD deficiency can lead a healthy and active life. Com as precauções direitas, uma criança com deficiência de G6PD pode levar uma vida saudável e ativa.

About G6PD Deficiency Sobre Deficiência G6PD

G6PD is one of many enzymes that help the body process carbohydrates and turn them into energy. G6PD é uma das muitas enzimas que ajudam o processo de hidratos de carbono do corpo e transformá-los em energia. 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. G6PD também protege as células vermelhas do sangue a partir de subprodutos potencialmente perigosos que podem acumular-se quando uma pessoa toma de certos medicamentos ou quando o corpo está lutando contra uma infecção.

In people with G6PD deficiency, either the RBCs do not make enough G6PD or what is produced cannot properly function. Em pessoas com deficiência de G6PD, seja das hemácias não fazem o suficiente G6PD ou o que é produzido pode não funcionar corretamente. Without enough G6PD to protect them, RBCs can be damaged or destroyed. Sem o suficiente G6PD para protegê-los, os glóbulos vermelhos podem ser danificados ou destruídos. 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. Anemia hemolítica ocorre quando a medula óssea (parte macio e esponjoso do osso que produz novas células do sangue) não pode compensar essa destruição, aumentando sua produção de hemácias.

Causes of G6PD Deficiency Causas de Deficiência de G6PD

G6PD deficiency is passed along in genes from one or both parents to a child. Deficiência de G6PD é passado ao longo de genes de um ou ambos os pais para uma criança. The gene responsible for this deficiency is on the X chromosome. O gene responsável por essa deficiência é no cromossomo X.

G6PD deficiency is most common in African-American males. Deficiência de G6PD é mais comum em Africano-americanos do sexo masculino. Many African-American females 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. Muitos Africano-Americano fêmeas são portadores de deficiência de G6PD, o que significa que pode passar o gene para a deficiência de seus filhos, mas não têm sintomas, apenas alguns são realmente afetados pela deficiência de G6PD.

People of Mediterranean heritage, including Italians, Greeks, Arabs, and Sephardic Jews, also are commonly affected. Pessoas de origem mediterrânea, incluindo italianos, gregos, árabes e judeus sefarditas, também são comumente afetados. The severity of G6PD deficiency varies among these groups — it tends to be milder in African-Americans and more severe in people of Mediterranean descent. A severidade da deficiência de G6PD varia entre esses grupos – que tende a ser mais leves em Africano-americanos e mais grave em pessoas de ascendência mediterrânica.

Why does G6PD deficiency occur more often in certain groups of people? Por que a deficiência de G6PD ocorrem com mais freqüência em determinados grupos de pessoas? It is known that Africa and the Mediterranean basin are high-risk areas for the infectious disease malaria. Sabe-se que a África ea bacia do Mediterrâneo são áreas de alto risco para a malária doenças infecciosas. Researchers have found evidence that the parasite that causes this disease does not survive well in G6PD-deficient cells. Os pesquisadores encontraram evidências de que o parasita que causa esta doença não sobrevive bem em G6PD deficiente células. So they believe that the deficiency may have developed as a protection against malaria. Assim, eles acreditam que a deficiência pode ter se desenvolvido como uma proteção contra a malária.

G6PD Deficiency Symptom Triggers

Kids with G6PD deficiency typically do not show any symptoms of the disorder until their red blood cells are exposed to certain triggers, which can be:

  • illness, such as bacterial and viral infections
  • certain painkillers and fever-reducing drugs
  • certain antibiotics (especially those that have “sulf” in their names)
  • certain antimalarial drugs (especially those that have “quine” in their names)

Some kids with G6PD deficiency can tolerate the medications in small amounts; others cannot take them at all. Check with your doctor for more specific instructions, as well as a complete list of medications that could pose a problem for a child with G6PD deficiency.

Other substances can be harmful to kids with this condition when consumed — or even touched — such as fava beans and naphthalene (a chemical found in mothballs and moth crystals). Mothballs can be particularly harmful if a child accidentally swallows one, so ANY contact should be avoided.

Symptoms of G6PD Deficiency

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 anemia (also known as a hemolytic crisis), including:

  • paleness (in darker-skinned children 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

Once the trigger is removed or resolved, the symptoms of G6PD deficiency usually disappear fairly quickly, typically within a few weeks.

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.

Diagnosing and Treating G6PD Deficiency

In most cases, cases of G6PD deficiency go undiagnosed until a child develops symptoms. If doctors suspect G6PD deficiency, blood tests usually are done to confirm the diagnosis and to rule out other possible causes of the anemia.

If you feel that your child may be at risk because of either a family history or your ethnic background, talk to your doctor about performing a screening with blood tests to check for G6PD deficiency.

Treating the symptoms associated with G6PD deficiency is usually as simple as removing the trigger — that is, treating the illness or infection or stopping the use of a certain drug. However, a child with severe anemia may require treatment in the hospital to receive oxygen, fluids, and, if needed, a transfusion of healthy blood cells. In rare cases, the deficiency can lead to other more serious health problems.

Caring for Your Child

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.

Reviewed by: Steven Dowshen, MD
Date reviewed: November 2009

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