The variants in the currently known HbF-modulating genes/loci, including BCL11A, the intergenic region between HBS1L and MYB (HBS1L-MYB), and the HBB locus, explain ≤16% of enhanced HbF expression after birth in African individuals with SCD (Makani et al., 2017; Wonkam et al., 2014). This evidence concerns the gene HBB and Schnyder corneal dystrophy.