Muscular dystrophy in female dogs

The most common form of muscular dystrophy in dogs and humans is caused by mutations in the dystrophin gene. The dystrophin gene is located on the X c hromosome. and, therefore a. disease-causing mutations in dystrophin occur most often in males. Therefore. females with dystrophin deficiency or other forms of muscular dystrophy may be undiagnosed or misdiagnosed. Immunohist ochemistry was used to analyze dystrophin and a number of other muscle prot eins associated with muscular dystrophy in humans. including sarcoglycans a nd laminin alpha2. in muscle biopsy specimens from 5 female dogs with patho logic changes consistent with muscular dystrophy. The female dogs were pres ented with a variety of clinical signs including generalized weakness. musc le wasting. tremors. exercise intolerance, gait abnormalities, and limb def ormity. Serum creatine kinase activity was variably high. One dog had no de tectable dystrophin in the muscle: another was mosaic, with some fibers nor mal and others partly dystrophin deficient. A 3rd dog had normal dystrophin but no detectable laminin alpha2. Two dogs could not be classified. This s tudy demonstrates the occurrence of dystrophin- and laminin alpha2-associar rd muscular dystrophy and the difficulty in clinical diagnosis of these di, orders in female dogs.