This large difference can be explained by the technique that was used (electrophoresis only at alkaline pH), given that the focus of the article was Hb S disease.22 This reinforces the need for an association of different tests in order to detect different hemoglobinopathies, especially electrophoresis at neutral pH and cytological investigation of Hb H inclusion bodies using brilliant cresyl blue, or even molecular testing. This evidence concerns the gene GSTM1 and hemoglobinopathy.