Low fetal hemoglobin rates in patients carrying Thai (δβ)0-deletion and Turkish (δβ)0-deletion/inversion strengthen the hypothesis that the 5'δ BCL11A binding site plays a major role in its fetal hemoglobin inhibitory regulation. Response to "The 12.6 kb-deletion in the β-globin gene cluster is the known Thai/Vietnamese (δβ)0-thalassemia commonly found in Southeast Asia".