Urinary beta-aminoisobutyric acid excretion in thalassaemia

The quantity of beta-aminoisobutyric acid (BAIB) excreted in the urine of patients with an intact spleen suffering from thalassaemia major appears to be proportional to the number of the circulating normoblasts and inversely proportional to the haemoglobin level. After splenectomy only minute amounts of BAIB are excreted. Transfusion constantly, but temporarily, reduces urinary excretion of beta-aminoisobutyric acid. Other anaemic but non-thalassaemic patients may excrete low levels.