DMD and Becker muscular dystrophy: The evidence that they may includes: (1) in one large family, isolated DCM in the absence of Duchenne or Becker muscular dystrophy mapped to the DMD gene (27), (2) a collection of case studies identified classically pathogenic DMD variants (exonic deletions or splice variants) in individuals with DCM and without additional features associated with muscular dystrophy (28–30), (3) a study which evaluated the DMD gene (called DYS in this paper) in a series of 436 male patients diagnosed with isolated DCM, the authors identified pathogenic deletions or splice variants in 34 patients (31).