Myotubular Myopathy 1, X-linked Myotubular Myopathy, XL-MTM

Affected puppies present with failure to thrive and weakness. This rapidly progresses to difficulty eating and breathing.

Signs first appear in puppies.

Genetic testing, clinical signs, and muscle biopsy can be used to diagnose this disorder.

Unfortunately, there is currently no treatment for XLMTM and owners often choose euthanasia.

Talk to your vet about your dog’s XL-MTM result so you can plan appropriate care and monitoring.

Signs such as weakness, difficulty breathing, or trouble nursing may appear early in life and tend to worsen over time.

Focus on keeping your puppy comfortable in a calm, supportive environment with easy access to food and water.

This condition is severe and progressive, but providing stability and gentle care can help keep your puppy comfortable.

This mutation was first characterized in the Labrador Retriever.

Penetrance: This mutation has a sex-linked recessive inheritance pattern, which means that the gene is on the X chromosome. Females have two X chromosomes and must inherit two abnormal copies to be affected with this disease. Males have only one X chromosome and either have a normal copy of the gene or the mutation.

Gene

MTM1 (Exon 7)

Inheritance type

X-linked recessive

Clinical category

Muscular

Citations

1. Beggs et al 2010

• English Labrador Retriever
• Labrador Retriever