X-Linked Myotubular Myopathy

X-linked myotubular myopathy (XLMTM) is a severe, inherited muscle disorder that predominantly affects Rottweilers and Golden Retrievers. This condition is characterized by progressive muscle atrophy, typically seen in puppies around 7 weeks. While puppies may appear normal at birth, the disease progresses rapidly, leading to significant muscle weakness and coordination issues. The disorder is linked to the X chromosome and manifests in males who inherit the mutated gene from their mother. Female dogs can be carriers of the mutation but usually do not show symptoms unless they inherit two copies of the defective gene.