Clinical signs include muscle tremors, pelvic limb stiffness, progressive weakness, and severe muscle atrophy. The age of onset was 3 to 9 months, and all were euthanized prior to 2 years of age due to painful muscular degeneration.  Serum creatine kinase activity was elevated in all affected dogs.  Histopathologic examination of muscle biopsies revealed multifocal areas of mixed mononuclear cell infiltration, myonecrosis and regeneration.  Metabolomics data from these five cases gives functional support to mitochondrial involvement. (from Canine Genetics Lab, U of MN)