Background: Glucose-6- phosphate dehydrogenase (G6PD) is an enzyme that plays a vital role in eliminating reactive oxygen species (ROS) which are considered to be toxic to the cells. Deficiency of this enzyme causes hemolysis. This study presents a case of a middle-aged woman with the late onset of G6PD with methemoglobinemia.
Case Presentation: A case of 57-year-old female was reported, who was presented to the emergency department with jaundice, dyspnea, dark urine and low oxygen saturation. On further investigation the patient's methemoglobin level reached up to 5.1%. Thus, the patient was diagnosed with the late onset of G6PD with methemoglobinemia.
Conclusion: The G6PD deficiency could present late in life especially in areas with mild variants. On rare occasions, it could be present with severe hemolysis associated with methemoglobinemia. In these cases, it is important to find the cause. The use of methylene blue as an antidote is harmful.
Key words: G6PD, methemoglobinemia, favism, deficiency, case report