1. Introduction
Definition: Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency is a genetic disorder characterized by a deficiency or dysfunction of the enzyme G6PD, which plays a crucial role in the Pentose Phosphate Pathway (PPP).
Inheritance: Typically inherited as an X-linked recessive trait, affecting males more frequently than females.
2. Role of G6PD in the Pentose Phosphate Pathway (PPP)
G6PD Function: G6PD is a key enzyme in the oxidative phase of the PPP, catalyzing the conversion of glucose-6-phosphate to 6-phosphoglucono-d-lactone while producing NADPH.
NADPH Production: NADPH generated by G6PD is essential for cellular antioxidant defense, protecting cells from oxidative stress.
3. Pathophysiology
Red Blood Cells (RBCs): G6PD deficiency affects red blood cells, making them susceptible to oxidative damage.
Hemolytic Anemia: The most common clinical manifestation triggered by exposure to oxidative stressors such as certain foods, medications, or infections.
Mechanism: G6PD-deficient RBCs are more vulnerable to oxidative stress due to the impaired ability to produce NADPH, leading to hemolysis (rupture) of red blood cells.
4. Clinical Features
Episodic Hemolysis: Patients may experience intermittent episodes of hemolysis triggered by specific factors.
Jaundice: Hemolysis releases bilirubin, leading to jaundice.
Splenomegaly: Enlargement of the spleen may occur due to increased removal of damaged red blood cells by the spleen.
5. Triggers for Hemolysis in G6PD Deficiency
Foods: Fava beans (broad beans) are a well-known trigger.
Medications: Certain drugs, including antimalarials, sulfa drugs, and some antibiotics, can induce hemolysis.
Infections: Illnesses and infections may lead to oxidative stress and trigger hemolysis.
6. Types of G6PD Deficiency
Several Variants: Numerous genetic variants of G6PD deficiency exist.
Severity: The severity of the condition can vary, with some individuals having mild deficiencies and others experiencing more severe symptoms.
7. Diagnosis
Enzyme Assay: G6PD activity can be measured in the laboratory through enzyme assays.
Genetic Testing: Molecular genetic testing can identify specific mutations associated with G6PD deficiency.
8. Treatment and Management
Avoidance of Triggers: Patients are advised to avoid known triggers, such as certain foods and medications.
Supportive Care: Treatment may involve supportive measures during severe hemolytic episodes, such as blood transfusions.
G6PD deficiency is a genetic disorder with significant implications for red blood cell function and overall health. While it poses challenges, ongoing research offers hope for improved diagnostics and potential therapeutic interventions. Genetic counseling and awareness are key components for effective management and support for individuals and families affected by G6PD deficiency.
