BCL11A and Schnyder corneal dystrophy: Naturally occurring genetic variants in the binding sites for the BCL11A or ZBTB7A repressor proteins, located around positions –115 and –200 of the γ-globin promoter, respectively, cause sustained postnatal transcription, resulting in a benign genetic condition termed Hereditary Persistence of Fetal Hemoglobin (HPFH), which can alleviate the symptoms of co-inherited SCD.19