Thalassemia

They affect different parts of hemoglobin. Alpha thalassemia depends on how many of the four alpha-globin genes are missing or changed. One missing gene makes a silent carrier. Two cause alpha thalassemia trait. Three cause hemoglobin H disease, with moderate to severe anemia. Four cause alpha thalassemia major, also called hydrops fetalis. Beta thalassemia involves the two copies of the HBB gene. One changed copy causes beta thalassemia trait (minor). Two cause beta thalassemia intermedia or major, which is also called Cooley’s anemia.

People with thalassemia trait, also called thalassemia minor, carry a changed thalassemia gene. NHLBI says they have mild or no symptoms and may not need treatment. CDC notes they can pass the gene to their children. Serious beta thalassemia is usually autosomal recessive: it happens when a child inherits a changed HBB gene from each parent. Thalassemia is most common in people with roots in the Mediterranean, the Middle East, Africa, South Asia and Southeast Asia.

A donor stem cell transplant can cure it. NHLBI notes that only a small number of people with severe thalassemia find a good donor match and are a good fit for the procedure. Since 2022, the FDA has also approved gene therapies made from the person’s own stem cells for beta thalassemia. Zynteglo was approved on August 17, 2022, for adults and children who need regular transfusions. Casgevy was approved on January 16, 2024, for people 12 and older with transfusion-dependent beta thalassemia, and in July 2026 for children as young as 2.

In a large European registry, a matched brother or sister gave the best results. The 2025 European EBMT recommendations say that when there is no matched sibling, a well-matched unrelated donor can give similar results and is a practical option. They add that transplants from half-matched relatives are increasingly done at experienced centers. EBMT also advises doing the transplant early in life, before iron overload causes lasting damage.

In part. In the European Union, Casgevy received a conditional marketing authorisation on February 9, 2024. It covers transfusion-dependent beta thalassemia in people aged 12 and older who are suitable for a transplant but have no HLA-matched related donor. The 2025 EBMT recommendations say it is available in only a few EU countries. Zynteglo was authorised in the EU in 2019, but the European Commission withdrew it on March 24, 2022, after the company stopped marketing it for commercial reasons. The approved gene therapies are for beta thalassemia; none is approved for alpha thalassemia.

Regular transfusions leave extra iron in the body, so iron chelation medicines remove it. NHLBI lists deferasirox and deferiprone, taken by mouth, and deferoxamine, given under the skin with a small pump. NHLBI also lists luspatercept (Reblozyl), which can reduce the number of transfusions needed, and hydroxyurea. In the U.S., the FDA has approved mitapivat (Aqvesme), a pill, for anemia in adults with alpha or beta thalassemia. It is available only through a safety program because of a risk of liver injury.

Some do, with treatment before birth. MedlinePlus Genetics says most babies with this form are stillborn or die soon after birth without treatment. An expert group reported in 2021 that blood transfusions given before birth can reverse the fluid buildup and help babies survive to birth. Many then have normal or near-normal development. After birth, care is similar to beta thalassemia major, with monthly transfusions. The experts say a stem cell transplant, when available and wanted by the parents, offers the possibility of a cure.