Immunohistochemical analysis on muscle biopsy from BM patient 1. Immunofluorescence analysis on muscle sections of BM Patient 1 (A-D) and control (E-H) of collagen VI (A, E), perlecan (B, F), laminin β1 (C, G) and collagen IV (D, H). A small reduction in collagen VI in the patient's endomysium (A) was observed in comparison with control (E). However, collagen VI was expressed normally around the blood vessels (arrows, A). Double-labeling with anti-perlecan antibody revealed a normal pattern (B) as well in the control section (F). Laminin β1 expression was reduced at the basal lamina of muscle fibers, while being expressed normally around the capillary walls (arrows, C). Collagen IV labeling showed a normal pattern around both vessels and muscle fibers (D). Bar, 40 μm.