A synonymous coding variant c.1437G>C/p.Arg479 = was reported in patients with X-linked sideroblastic anemia (XLSA), where the ALAS2 mRNA transcribed from the c.1437C allele is spliced less efficiently and/or degraded via nonsense-mediated decay [39]. Here, ALAS2 is linked to X-linked sideroblastic anemia 1.