A new β(0) frameshift mutation, HBB: c.44delT (p.Leu14ArgfsX5), identified in an Argentinean family associated with secondary genetic modifiers of β-thalassemia.

β-Thalassemia intermedia (β-TI) patients present with a wide spectrum of phenotypes depending on the presence of primary, secondary, and tertiary genetic modifiers which modulate, by different mechanisms, the degree of imbalance between α and β chains. Here we describe a new β(0) frameshift mutation, HBB: c.44delT (p.Leu14ArgfsX5), identified in four members of a family, associated with secondary genetic modifiers in three of them. The different genotype present in this family was suspected after hematological analysis and thorough observation of blood smears highlighting their importance in the identification of β-TI patients among members of the same family.