Mitochondrial dysfunction syndrome 3 (MMDS3)

General Information: Mitochondrial Dysfunction Syndrome 3 (MMDS3) is an inherited disorder in dogs caused by mutations in the IBA57 gene. This condition affects the mitochondria, which are essential for energy production in cells. Dogs with two copies of the associated gene mutation are predisposed to this condition, which typically manifests early in life. Symptoms include severe muscle weakness, lack of coordination, tremors, and difficulty walking. Affected dogs may also exhibit lethargy, poor growth, and seizures. Since mitochondria are vital to many tissues, the disorder can lead to multi-organ dysfunction, especially impacting muscles and the nervous system. This condition can severely reduce a dog’s quality of life, and early intervention with supportive care may be necessary, though there is currently no cure for MMDS3.

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 the IBA57 gene mutation can determine whether a dog is at risk for developing Mitochondrial Dysfunction Syndrome 3. This disorder is inherited in an Autosomal Recessive manner, meaning dogs must inherit two copies of the mutated gene, one from each parent, to develop the disease. Carrier dogs, with only one copy of the mutation, do not exhibit symptoms but can pass the mutation to their offspring. When two carriers are bred, each pup has a 25% chance of being affected and a 50% chance of being a carrier. Reliable genetic testing is essential for responsible breeding practices, as breeding two carriers increases the risk of producing affected puppies. Dogs that are not carriers have no increased risk of producing affected offspring.