X Linked Myotubular Myopathy In Rottweiler Dogs
By : G Diane Shelton, Branden E Rider, Georgina Child, Sophia Tzannes, Ling T Guo, Behzad Moghadaszadeh, Emily C Troiano, Bianca Haase, Claire M Wade and Alan H Beggs
Congenital and inherited myopathies in dogs are faithful models of human muscle diseases and are being recognized with increasing frequency. In fact, canine models of dystrophin deficient muscular dystrophy and X-linked myotubular myopathy are of tremendous value in the translation of new and promising therapies for the treatment of these diseases. We have recently identified a family of Australian Rottweilers in which male puppies were clinically affected with severe muscle weakness and atrophy that resulted in early euthanasia or death. X-linked myotubular myopathy was suspected based on the early and severe clinical presentation and histopathological changes within muscle biopsies. The aim of this study was to determine the genetic basis for myopathy in these dogs and compare and contrast the clinical presentation, histopathology, ultrastructure, and mutation in this family of Rottweiler dogs with the previously described myotubular myopathy in Labrador retrievers.
Here we describe a second pathogenic mutation in MTM1 causing X-linked myotubular myopathy in dogs. Our findings suggest a variety of MTM1 mutations in dogs as seen in human patients. The number of MTM1 mutations resulting in similar severe and progressive clinical myopathy and histopathological changes are likely to increase as canine myopathies are further characterized.