Is the β thalassaemia trait of clinical importance?

Although the β thalassaemia trait affects millions of people worldwide, there have been no controlled studies to determine whether it is associated with any clinical disability or abnormal physical signs. To address this question, 402 individuals were studied: 217 with β thalassaemia trait, of whom 154 were aware of the diagnosis and 63 were unaware until after the completion of the study; 89 normal controls; and 96 controls with mild hypochromic anaemia. There was a significant increase in symptoms ascribable to anaemia and episodes of pyrexia in those with the β thalassaemia trait that were not influenced by prior knowledge that they had this condition. There was no difference in physical findings, notably splenomegaly, between those with β thalassaemia trait and either control group. © 2008 The Authors.