Molecular and Hematological Characterization of Two Novel δ-Globin Gene Mutations Found in Chinese Individuals

We identified two novel δ-globin gene mutations in two families during routine thalassemia screening. One missense mutation at codon 73 on the δ-globin gene [δ73(E17)Asp→Val, HBD: c.221A>T] which results in a Hb A₂ variant homologous to the β-globin gene variant called Hb Mobile [β73(E17)Asp→Val, HBB: c.221A>T] and we have named this variant Hb A₂-Henan. The other is a nonsense mutation [δ7(A4)Glu→Stop, HBD: c.22G>T] which gives rise to a stop codon (TAG) at codon 7, resulting in δ⁰-thalassemia (δ⁰-thal). The Hb A₂ in one individual with homozygous HBD: c.22G>T was absent.