Characterization of a novel deletion causing (δβ) ⁰-thalassemia in a Thai family

Abstract

A novel deletion of the human β-globin gene cluster associated with the increased level of fetal hemoglobin (Hb F) in adult life has been demonstrated in a Thai family. A Thai girl who was mistakenly diagnosed as β-thalassemia/HbE is found to be the compound heterozygote of this mutation and Hb E. The heterozygous father had mild hypochromic and microcytic red blood cells and a high level of Hb F (23.2%). Polymorphic restriction sites in the β-globin gene cluster identified the homozygous alleles, which localized the deletion region between the ψβ-globin and the 3′ β-globin genes. DNA polymerase that can amplify a long DNA template was employed to examine DNA fragment encompassing this deletion. A 11.3 kilobases (kb) of DNA deletion, beginning ∼3.1 kb 5′ to the δ-globin gene and end in the intron 2 of the β-globin gene was detected. DNA analysis revealed that this is a case of (δβ)0-thalassemia with a novel mutation, which can lead to a mild form of β-thalassemia upon interaction with Hb E. © 2006 Wiley-Liss, Inc.