Ringed sideroblasts in β-thalassemia

Abstract

Symptomatic β-thalassemia is one of the globally most common inherited disorders. The initial clinical presentation is variable. Although common hematological analyses are typically sufficient to diagnose the disease, sometimes the diagnosis can be more challenging. We describe a series of patients with β-thalassemia whose diagnosis was delayed, required bone marrow examination in one affected member of each family, and revealed ringed sideroblasts, highlighting the association of this morphological finding with these disorders. Thus, in the absence of characteristic congenital sideroblastic mutations or causes of acquired sideroblastic anemia, the presence of ringed sideroblasts should raise the suspicion of β-thalassemia.

Keywords: ringed sideroblasts; sideroblastic anemia; thalassemia.

Figure 1. Siderocytes and ringed sideroblasts in patients with β-thalassemias

(A) Iron-stained peripheral blood smear from patient 1 demonstrating hypochromic microcytic anemia with numerous nucleated RBCs and abundant sideroctyes. (B &C) Iron-stained bone marrow aspirates from patients 5 and 6, respectively showing coarse perinuclear deposits of iron, typical of ringed sideroblasts. (D) Diagram of the α-globin locus and flanking regions on human chromosome 16. Genes are indicated by black bars and regions duplicated in families 1 and 2 are indicated by gray bars.