Indeed, for instance, polymorphisms in important ɤ-globin-regulating loci (e.g., BCL11A and HBS1L-MYB) leading to ɤ-globin persistence into adulthood can ameliorate the clinical severity of SCD (Lettre et al., 2008; Creary et al., 2009; Makani et al., 2011; Sokolova et al., 2019). This evidence concerns the gene BCL11A and Schnyder corneal dystrophy.