Abstract
We describe a case of Hb S/β-thalassemia (thal) involving a 468 bp deletion that removes the β-globin gene promoter but leaves the coding regions intact. This is the second report of this deletion, and our family study establishes that this deletion causes β0-thal with unusually high levels of Hb A2 and Hb F. As with other genotypes involving deletions of the 5′ region of the β-globin gene, our patient had a mild form of Hb S/β-thal.