We report the first identification of a point mutation located within the promoter region of the beta-globin gene at position -83 (G>A) and associated with the common heterozygous deletional alpha-thalassemia (alpha-thal) (-alpha(3.7)/alphaalpha). 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 A(2) level at the upper limit of the normal value (3.5%). This observation is a new example of alpha- and beta-thal co-inheritance with a normal Hb A(2) level, and illustrates a potential source of pitfall in screening for alpha- and beta-thal carriers.