Multiplex ligation-dependent probe amplification (MLPA) can beused to detect rearrangements that cause α-thalassemia, particularly largedeletions involving the whole α cluster and/or deletions in the HS-40 region.Here, MLPA was used to investigate the molecular basis of α-thalassemia in fiveunrelated patients, three of whom had Hb H disease. This evidence concerns the gene GSTM1 and glycogen storage disease VI.