GDF15 and thalassemia: Although thalassaemia trait is considered an asymptomatic condition, evidence suggests it may be associated with increased erythropoiesis, increased soluble transferrin receptor levels, low hepcidin and high GDF15.249 Similarly, there is evidence that mild anaemia in thalassaemia trait could be significant, especially in states of high metabolic demand, for instance in pregnancy, affecting the offspring.