Description: GRMD is a degenerative muscular disease causing loss of active muscular tissue and movement disorders.  In humans, this syndrome is known as Duchenne´s muscular dystrophy (DMD). The disease is characterized by a deficiency of dystrophin in skeletal muscles caused by a mutation in DMD gene.

The dystrophin is a cytoskeletal protein that fixes actin to the extracellular laminin. The absence of dystrophin can cause degradation of exocytosis, which can destabilize the cytoplasmic membrane. The result of these steps is that intracellular calcium is released, endogenous proteases are activated, and inflammatory cascades starts.

Typical clinical signs of muscular dystrophy include muscle weakness, impaired walking or swallowing and breathing difficulty. The disease is progressive and very often ends with death.  The affected dogs show muscle atrophy, elevated levels of serum creatine kinase, degeneration and mineralization of hyaline myofibrils, muscular fibrosis with fat infiltrations and cardiomyopathy. GRMD is usually expressed in puppies around 8 weeks of age. Dogs with a severe form of the disease die soon after diagnosis, while dogs with a milder form of the disease can survive several years.

The genotype of males is X and Y. For the development of GRMD it is enough for them to have just one affected allele. It means that males can be non-affected (Xn/Y) or affected (Xm/Y), but not carriers.

The genotype of females is XX. They can be non-affected (Xn/Xn), affected (Xm/Xm) or carriers (Xn/Xm) when they have one allele with the mutation but the other one is clear. Carrier individuals have no clinical symptoms, but they can transfer GRMD to the next generation.

 

Inheritance: X-linked recessive

 

Mutation: c.531-2A>G mutation in DMD gene

 

Sample: EDTA whole blood (1.0 ml) or 2 buccal brushes. For official purposes, the confirmation of the dog’s identity by Veterinarian is recommended.

The analysis is suitable for the following breeds: Golden retriever

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