DMD and Duchenne muscular dystrophy: Examples of well-established genotype-phenotype correlations within the DMD spectrum include several mutations linked to milder DMD, or IMD, such as deletion of exons 3–7 (Muntoni et al., 1994; Winnard et al., 1995; Gualandi et al., 2006; Bello et al., 2016a) or other deletions bordering exon 8 (Wang et al., 2018).