Identification of a New Mutation on the β-Globin Gene: Codons 8/9 (+AGAA); GAG.AAG.TCT(Glu-Lys-Ser)>GAG. AAAGAAG, in a Patient From the North of France with a Phenotype of β-Thalassemia Minor

Abstract

A 37-year-old man presented a slight debility. The hemogram showed a phenotype of β-thalassemia minor: Hb (13.1 g/dL), mean corpuscular volume (MCV) (62 fL) with low mean corpuscular hemoglobin (MCH) (20.8 pg), associated with a high level of Hb A₂ of 5.3%. The serum ferritin level was 1,072 ng/mL. The sequencing of the mutated fragment revealed a duplication of four bases of codons 7/8 involving a shift in the open reading frame starting from codon 9 with a TGA stop codon at codon 23: codons 7/8/9 (+AGAA); GAG.AAG.TCT(Gly-Lys-Ser)>GAG.AAAGAAG. The human hemoglobin (Hb) instability tests were negative. The patient did not present the high iron Fe (HFE) mutation (C282Y, H63D). The same mutation was found in five other unrelated families (representing a total of 23 patients). All of their ancestors came from the north of France. This mutation has not been described before and could have its origins in the native populations of Northern France.

Keywords:

• β-Thalassemia (β-thal)
• β-Globin gene
• North-European mutation