The Berkeley SCD mouse harbors genetic disruptions of endogenous adult-type α- and β-globin genes (Hbb-a1, Hbb-a2, Hbb-bmaj and Hbb-bmin) and expresses human globins via three DNA transgenes: 1.5 kb spanning the α-globin gene HBA1; a contiguous 39 kb genomic fragment including genes for γ-globin (HBG2, HBG1), δ-globin (HBD) and sickle β-globin (HBBS); and a 6.5 kb ‘mini-locus control region (LCR)’ derived from an endogenous enhancer in the human β-like globin cluster that confers high-level erythroid expression (Pászty et al., 1997). The gene discussed is HBB; the disease is Schnyder corneal dystrophy.