"Silent" ?-thalassemia mutation (promoter nt-101 C > T) with increased hemoglobin A2

Abstract

Aslan D. "Silent" ?-thalassemia mutation (promoter nt-101 C > T) with increased hemoglobin A2. Turk J Pediatr 2016; 58: 305-308.One of the most common silent ?-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 ?-globin gene. Carriers of this mutation have a normal hematologic picture without microcytosis and borderline hemoglobin A2 values, and may be missed during screening. Cooccurrence of this mutation with one of the classical ?-thalassemia mutations leads to ?-thalassemia intermedia, and this is important for Mediterranean populations where ?-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.