First Identification of a Point Mutation at Position −83 (G>A) of the β-Globin Gene Promoter

Abstract

We report the first identification of a point mutation located within the promoter region of the β‐globin gene at position −83 (G>A) and associated with the common heterozygous deletional α‐thalassemia (α-thal) (−α^3.7/αα). The patient was an adult male from Gabon belonging to the Obamba sub ethnic group, who was referred to our clinics for a mild microcytic anemia with a Hb A₂ level at the upper limit of the normal value (3.5%). This observation is a new example of α- and β-thal co-inheritance with a normal Hb A₂ level, and illustrates a potential source of pitfall in screening for α- and β-thal carriers.

Keywords:

• β-Thalassemia (β-thal)
• β-Globin mutation
• β-Globin promoter
• Hb A₂