δ-Thalassemia with Complete Absence of Hb A2in a Chinese Family

A Chinese family with δ-thalassemia (δ-thal) was found, in which the daughter is homozygous for δ-thal (HBD: c.-127T>C) with complete deficiency of Hb A2 and the mother is a heterozygote with low level of Hb A2. The father, however, is a heterozygote with a normal Hb A2 value due to coinheritance of a β-thalassemia (β-thal). Although no abnormal clinical or hematological findings were noted in the individuals with δ-thal, one should keep in mind that β-thal can be missed during routine preliminary screening when β-thal and δ-thal coexist in a subject.