Small muscle protein, X-linked (SMPX) plays a role in skeletal muscle hypertrophy34, and Protein phosphatase 3 catalytic subunit alpha (PPP3CA) plays a critical role in controlling skeletal muscle fiber type35, while abnormal splicing of the penultimate exon of dystrophin (DMD) compromises muscle fiber maintenance in myotonic dystrophy36. This evidence concerns the gene SMPX and Duchenne muscular dystrophy.