In vitro, CRISPR-mediated disruption of non-coding variants associated with X-linked sideroblastic anemia and pyruvate kinase deficiency revealed that even small (2–4 nt) changes in GATA1 binding sites reduce GATA1 binding and impair recruitment of cofactors like TAL1 [118]. Here, GATA1 is linked to Hemolytic anemia due to red cell pyruvate kinase deficiency.