Children with beta thalassemia major, also called Cooley's anemia, usually develop clinical signs during their first year of life. They appear to be malnourished and may exhibit abdominal girth expansion. They show bone marrow expansion and skeletal deformations, which are a result of increased erythropoiesis due to low hemoglobin levels. A common finding is facial bone changes caused by this bone marrow expansion (sometimes referred to as Mongoloid facial features).
Other clinical signs include frequent infections, hepatomegaly, splenomegaly, gall stones, leg ulcers, iron toxicity, and poor growth and sexual development. In addition, cardiac failure due to increased burden of the heart attempting to oxygenate the tissues, can lead to serious complications and death if the condition is not treated.
In general, death usually occurs by the time these patients are in their early twenties unless treated with blood transfusions along with iron-chelating agents. If no chelating agent is used during treatment life will only be prolonged by about a decade.
The different genotypes associated with beta thalassemia major are: B0/B0, B0/B+, or B+/B+.