'Silent' beta-thalassemia mutation (promoter nt-101 C T) with increased hemoglobin A(2)

摘要

One of the most common silent beta-thalassemia mutations is the C T substitution at position - 101 within the distal CACCC box, which leads to a mild reduction in the expression level of the beta-globin gene. Carriers of this mutation have a normal hematologic picture without microcytosis and borderline hemoglobin A2 values, and may be missed during screening. Co-occurrence of this mutation with one of the classical beta-thalassemia mutations leads to beta-thalassemia intermedia, and this is important for Mediterranean populations where beta-thalassemia is frequent. Awareness of this mutation, which may have a heterogeneous clinical presentation, is required. We herein present the unusual hematologic findings of a Turkish family carrying this mutation.