Thalassemia Intermedia Due to a Novel Mutation in the Second Intervening Sequence of the β-Globin Gene

We describe a new β-thalassemia (thal) mutation in the β-globin gene of an 8-year-old Moroccan boy. This homozygous mutation produces a phenotype of thalassemia intermedia and is associated with the Mediterranean haplotype IX. We discuss the pathophysiological consequences of this mutation which is located near the 3 ′ end of the second intervening sequence (IVS-II) of the β-globin gene.