Analysis of muscle biopsies from juvenile-onset patients. Muscle fibers were stained for lysosomal marker LAMP2 (green) and autophagosomal marker LC3 (red). LAMP2/LC3 immunostaining demonstrates variability of muscle fiber involvement: completely destroyed fibers in pts. HM3 (a) and HM1 (d); a typical well- preserved fiber in pt. CLINM (b); fibers with inclusions in pts. HM1 and HM5 (c and e respectively), and a fiber with lysosomal enlargement in pt. HM1 (c; arrowheads). Bar: 10 μm.