Analysis of (δβ)0 Thalassemia and HPFH Deletions Suggest a Hierarchy of Cis-Acting Elements Regulating Fetal Hemoglobin Gene Expression.

Abstract Hereditary persistence of fetal hemoglobin (HPFH) and (δβ)0 thalassemia are caused by deletions within the β-globin gene (HBB) cluster that remove elements that affect the expression of the γ-globin genes (HBG2 and HBG1, or HBG). These deletions are of different lengths and have different 5’ and 3’ breakpoints. The phenotypes associated with heterozygous carriers of (δβ)0 thalassemia and HPFH deletions are …