We thank Drs Baklouti and Delaunay for the interest they showed in our work. Nevertheless, we were perfectly aware of the possibility that an HbS level below 15% could be explained by a β-thal. mutation in cis of the β chromosome.
Indeed, one of the co-authors of the article in the American Journal of Hematology cited by Drs Baklouti and Delaunay1 is Dr. Alain Francina who is a member of our team and who is acknowledged in our paper for his advice on methodology.
Consequently, of course we sequenced the HBB gene promoter entirely but we did not find any abnormality.