Anemia is a condition characterized by a deficiency in the number or quality of red blood cells (RBCs) or hemoglobin, leading to decreased oxygen transport to the body's tissues.
Anemia can be classified based on its cause into hereditary (genetic) and acquired types.
Hereditary Anemia
Hereditary anemias are caused by genetic mutations that affect the production, structure, or function of RBCs.
Common types include:
1. Sickle Cell Anemia:
A mutation in the HBB gene leading to the production of abnormal hemoglobin S.
2. Thalassemia:
Mutations in the genes that produce alpha or beta globin chains of hemoglobin.
3. Hereditary Spherocytosis:
Mutations in genes encoding RBC membrane proteins, causing spherical RBCs that are prone to hemolysis.
4. Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency:
A deficiency in the G6PD enzyme, leading to RBC vulnerability to oxidative stress and hemolysis.
Pathophysiology
1. Sickle Cell Anemia:
Abnormal hemoglobin causes RBCs to sickle under low oxygen conditions, leading to vaso-occlusion and hemolysis.
2. Thalassemia:
Imbalanced globin chain production results in ineffective erythropoiesis and hemolysis.
3. Hereditary Spherocytosis:
Defective membrane proteins lead to spherical RBCs that are destroyed in the spleen.
4. G6PD Deficiency:
Lack of G6PD enzyme impairs the RBCs' ability to handle oxidative stress, leading to hemolysis.
Symptoms
1. General Anemia Symptoms:
Fatigue, pallor, shortness of breath, and dizziness.
2. Specific to Each Type:
Sickle Cell Anemia: Pain crises, swelling, frequent infections.
Thalassemia: Bone deformities, growth retardation, splenomegaly.
Hereditary Spherocytosis: Jaundice, splenomegaly.
G6PD Deficiency: Hemolytic episodes triggered by certain foods, infections, or medications.
Diagnosis
1. Blood Tests:
CBC, peripheral blood smear, reticulocyte count.
2. Specific Tests:
Hemoglobin electrophoresis, genetic testing, enzyme assays.
Treatment
Sickle Cell Anemia: Pain management, hydroxyurea, blood transfusions, bone marrow transplant.
Thalassemia: Blood transfusions, iron chelation, folic acid supplements, bone marrow transplant.
Hereditary Spherocytosis: Splenectomy, folic acid supplements.
G6PD Deficiency: Avoidance of triggers, supportive care during hemolytic episodes.