MINITASK 1 GP sends a 2-year-old-boy with a mild hypotonia and slight disharmony of the psychomotor development for an accidental finding of hyper-CK-emia (CK 270 ukat/l, AST 1,2 ukat/l, ALT 0,87 ukat/l, myoglobin strictly normal) Suggest a diferencial diagnostic process and focus on the most effective sequence of the paraclinic examinations