[4] Symptoms depend on the extent to which hemoglobin is deficient, and include anemia, pallor, tiredness, enlargement of the spleen, iron overload, abnormal bone structure, jaundice, and gallstones.

[5][6] The disease is characterised by reduced production of the alpha-globin component of hemoglobin, caused by inherited mutations affecting the genes HBA1 and HBA2.

[5] Diagnosis is by checking the medical history of near relatives, microscopic examination of blood smear, ferritin test, hemoglobin electrophoresis, and DNA sequencing.

[5] As an inherited condition, alpha thalassemia cannot be prevented although genetic counselling of parents prior to conception can propose the use of donor sperm or eggs.

[8] The principle form of management is blood transfusion every 3 to 4 weeks, which relieves the anemia but leads to iron overload and possible immune reaction.

[28] If thalassemia is untreated or undetected in the infant, this can lead to developmental issues such as slowed growth, delayed puberty, bone abnormalities, and intellectual impairment.

This expansion is a compensatory response to the damage caused to red blood cells by the imbalanced production of globin chains.

Expansion of the bone marrow in the developing child leads to a distinctive facial shape often referred to as "Chipmunk facies".

[25][34] People with thalassemia can get too much iron in their bodies, either from the disease itself as RBCs are destroyed, or as a consequence of frequent blood transfusions.

Symptoms include an irregular heartbeat, cardiomyopathy, cirrhosis of the liver, hypothyroidism, delayed puberty and fertility problems, brittle and deformed bones, and an enlarged spleen.

[36][37] The spleen is the organ which removes damaged red blood cells from circulation; in thalassemia patients it is abnormally active, causing it to enlarge and possibly become hyperactive, a condition called hypersplenism.

[25][39] Checking for hemoglobinopathies begins during pregnancy, with a prenatal screening questionnaire which includes, among other things, a consideration of health issues in the child's parents and close relatives.

[40][41] A routine heel prick test, in which a small sample of blood is collected a few days after birth, can detect some forms of hemoglobinopathy.

Those with mild alpha thalassemia, involving deletion of one or two alpha-globin genes, do not generally require treatment and have a normal life expectancy.

Hemoglobin H disease, with three of the four genes either deleted or inactive, gives a mild to moderate form of anemia but may lead normal lives.

[54][55] Multiple blood transfusions lead to severe iron overload, as the body eventually breaks down the hemoglobin in donated cells.

[59] Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for both alpha and beta thalassemia.

Cells are ideally sourced from human leukocyte antigen matched relatives; the procedure is more likely to succeed in children rather than adults.

Since then, a number of patients have received bone marrow transplants from healthy matched donors, although this procedure has a high level of risk.

[63] In 2018 an unborn child with hydrops fetalis, a potentially fatal complication of alpha thalassemia, was successfully transfused in utero with her mother's stem cells.

[65] In one study of 31 people, the procedure was successful for 22 whose hemoglobin levels improved to the normal range, in seven the graft failed and they continued to live with thalassemia, and two died of transplantation-related causes.