Glucose-6-Phosphate Dehydrogenase Deficiency

Key Features

• African, Mediterranean, or Asian ancestry

• Neonatal hyperbilirubinemia

• Sporadic hemolysis associated with infection or with ingestion of oxidant drugs or fava beans

• X-linked inheritance

Clinical Findings

• Infants may have significant hyperbilirubinemia

• Older children are asymptomatic and appear normal between episodes of hemolysis

• Hemolytic episodes are often triggered by infection or by the ingestion of oxidant drugs such as antimalarial compounds and sulfonamide antibiotics

• Episodes of hemolysis are associated with

  • Pallor

  • Jaundice

  • Hemoglobinuria

  • Cardiovascular compromise (sometimes)

Diagnosis

• Hemoglobin concentration, reticulocyte count, and peripheral blood smear are usually normal in the absence of oxidant stress

• Episodes of hemolysis are associated with a variable fall in hemoglobin

• "Bite" cells or blister cells may be seen, along with a few spherocytes

• Hemoglobinuria is common

• Reticulocyte count increases within a few days

• Heinz bodies may be demonstrated with appropriate stains

• Diagnosis is confirmed by finding reduced levels of G6PD in erythrocytes

Treatment

• Drugs known to be associated with hemolysis should be avoided

• For some patients of Mediterranean, Middle Eastern, or Asian ancestry, the consumption of fava beans must also be avoided

• Infections should be treated promptly and antibiotics given when appropriate

• Most episodes of hemolysis are self-limiting

• Red cell transfusions may be lifesaving when signs and symptoms indicate cardiovascular compromise