Myotubular Myopathy 1 (Boykin Spaniel Type)

General Information: Myotubular Myopathy 1 (MTM1) in Boykin Spaniels is a debilitating genetic condition evident in early puppyhood, around 7 to 13 weeks of age. The disorder is characterized by progressive muscle weakness, notably diminished muscle mass, and significant exercise intolerance. Puppies display physical difficulties such as struggling to stand, maintain head posture, or move smoothly, with some exhibiting distinctively bent or crinkled whiskers. The progression is rapid, often leading to severe incapacity including the inability to stand or lift their heads within a few weeks from the onset of symptoms. While the condition itself is not painful, it severely impacts the quality of life, leading to early euthanasia or natural death due to complications related to immobility.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing for Myotubular Myopathy 1 (MTM1) in Boykin Spaniels focuses on the MTM1 gene, identifying carriers and affected individuals. MTM1 is unique in its X-linked inheritance pattern. Male dogs need only one mutated gene from their mother to be affected, making the disease much more common and severe in males than in females, who must inherit two mutated genes (one from each parent) to exhibit symptoms. Genetic testing can precisely identify carrier females and affected males, guiding breeding decisions to prevent the transmission of this mutation. It is advised against breeding carrier females to prevent producing affected male offspring. Testing ensures that affected males or carrier females are not used for breeding, crucial for reducing the prevalence of this debilitating condition in future generations.