First Description in Tunisia of a Point Mutation at Codon 119 (CCT→TCT) in the α1-Globin Gene: Hb Groene Hart in Association with the − α^3.7 Deletion

Abstract

Herein we describe the case of a Tunisian girl who presented with 3% Hb Bart's (γ₄) at birth. At the age of 3 years, she showed microcytosis and hypochromia in the absence of iron deficiency. The first step of molecular analysis was to test for the common Mediterranean mutations and the classical − α^3.7 deletion was found in the heterozygous state. Since this finding could not explain the level of Hb Bart's at birth, or the hypochromia and microcytosis, all the α-globin genes were sequenced. This revealed a rare point mutation at codon 119 (CCT→TCT) in the α1-globin gene, identified for the first time in Tunisia, and which has previously been described as an unstable hemoglobin (Hb) variant named Hb Groene Hart [α119(H2)Pro→Ser (α1)]. Here the − α^3.7/αα^{119(CCT→TCT)} genotype is responsible for the α-thalassemia (thal) trait phenotype.

• α-Thalassemia (thal)
• Tunisia
• Point mutation