The increase in haemoglobin A2 (HbA2) level is the most important laboratory parameter for the identification of carriers of beta thalassaemia, and is considered diagnostic in the appropriate clinical context.3 Accurate quantification of HbA2 in the haematology laboratory is therefore essential to allow for routine diagnosis of the beta thalassaemia trait.4 This highlights the value of reliable reference intervals. This evidence concerns the gene HBA2 and beta thalassemia.