Becker Muscular Dystrophy-Like Myopathy Regarded as So-Called “Fatty Muscular Dystrophy” in a Pig: A Case Report and Its Diagnostic Method

• DOI: 10.1292/jvms.13-0336
• Publication Date: 2013-10-27T23:04:10Z
• Authors: Noriyuki HORIUCHI; Naoyuki AIHARA; Hiroshi MIZUTANI; Shinichi KOUSAKA; Tsuneyuki NAGAFUCHI; Mariko OCHIAI; Kazuhiko OCHIAI; Yoshiyasu KOBAYASHI; Hidefumi FURUOKA; Tetsuo ASAI; Koji OISHI
• Keywords: Electrophoresis, Agar Gel; Swine Diseases; 0301 basic medicine; Swine; Histological Techniques; Fluorescent Antibody Technique; Muscular Dystrophy, Animal; Polymerase Chain Reaction; 3. Good health; Dystrophin; 03 medical and health sciences; Sarcolemma; Japan; Pathology; Animals; Muscle, Skeletal; DNA Primers

We describe a case of human Becker muscular dystrophy (BMD)-like myopathy that was characterized by the declined stainability of dystrophin at sarcolemma in a pig and the immunostaining for dystrophin on the formalin-fixed, paraffin-embedded (FFPE) tissue. The present case was found in a meat inspection center. The pig looked appeared healthy at the ante-mortem inspection. Muscular abnormalities were detected after carcass dressing as pale, discolored skeletal muscles with prominent fat infiltrations and considered so-called "fatty muscular dystrophy". Microscopic examination revealed following characteristics: diffused fat infiltration into the skeletal muscle and degeneration and regeneration of the remaining skeletal muscle fibers. Any lesions that were suspected of neurogenic atrophy, traumatic muscular degeneration, glycogen storage disease or other porcine muscular disorders were not observed. The immunostaining for dystrophin was conducted and confirmed to be applicable on FFPE porcine muscular tissues and revealed diminished stainability of dystrophin at the sarcolemma in the present case. Based on the histological observations and immunostaining results, the present case was diagnosed with BMD-like myopathy associated with dystrophin abnormality in a pig. Although the genetic properties were not clear, the present BMD-like myopathy implied the occurrence of dystrophinopathy in pigs. To the best of our knowledge, this is the first report of a natural case of myopathy associated with dystrophin abnormalities in a pig.