Thalassemia is a blood disorder caused by variants or missing genes that affect hemoglobin production. There are two main types: alpha thalassemia affects alpha globin gene expression, while beta thalassemia is caused by a deficiency in beta globin production. People with beta thalassemia experience anemia and other health issues due to the lack of functional hemoglobin in red blood cells. Treatment involves regular blood transfusions combined with iron chelation therapy or bone marrow transplants in severe cases.