Beta thalassemia

Beta thalassemia is an inherited blood disorder that reduces or eliminates the body's ability to produce the beta-globin chains needed to build normal adult hemoglobin, the protein red blood cells use to carry oxygen. It results from mutations in the HBB gene on chromosome 11, of which more than 350 different variants are known to cause disease, and the severity a person experiences depends heavily on whether one or both copies of the gene are affected: people with a single affected copy are often symptom-free carriers, while those with two affected copies can develop severe, transfusion-dependent anemia. Common effects in more severely affected people include chronic anemia, pale skin, persistent tiredness, an enlarged spleen, jaundice and gallstones, along with longer-term complications such as bone deformities from the body's compensatory overproduction of red cells, developmental delay, and organ damage from iron buildup, which without treatment can progress to fatal heart failure. Diagnosis draws on a complete blood count showing small, hemoglobin-poor red cells, hemoglobin electrophoresis to identify the abnormal hemoglobin pattern, iron studies, and DNA testing to confirm the specific HBB mutations involved. Management of the more severe forms centers on regular blood transfusions paired with iron chelation therapy to prevent iron overload, along with folic acid supplementation and, in some cases, removal of the spleen; stem cell transplantation and newer gene therapies aimed at correcting the underlying HBB defect offer the possibility of a lasting cure for some patients.