DMD and familial dilated cardiomyopathy: Based on the previous case reports, the DMD gene mutations occurring with XLDCM or mild BMD with DCM, have been classified into the following four regions: (1) The region from the muscle promoter to muscle exon 1; (2) The region from exon 2−8 region coding the actin binding domain; (3) The region from exon 45−55, (considered the “hot spot” for mutations in the DMD gene) coding the rod domain; and (4) The remaining region.