Duchenne-type muscular dystrophy / DMD (DMD-related) - Cavalier King Charles Spaniel

What does this test examine?

This genetic test detects the DMD c.7293+5G>T variant that causes Duchenne-type muscular dystrophy in the Cavalier King Charles Spaniel. The condition is also described as DMD, X-linked muscular dystrophy, dystrophinopathy, dystrophin-deficient muscular dystrophy and DD-MD.

What does this condition mean?

DMD encodes dystrophin, a protein that protects muscle fibres during movement. When functional dystrophin is absent, muscle fibres are easily damaged. Affected dogs develop progressive muscle weakness, abnormal gait, reduced exercise tolerance, swallowing or chewing problems and muscle wasting. Severe Duchenne-type forms can be serious and life-threatening.

Inheritance and result

This trait is X-linked recessive. Male dogs have one X chromosome: a male with the variant on his X chromosome is genetically affected. Females with one copy are carriers and can pass the variant on; females with two copies are genetically positive.

For this variant, result labels are shown as G/G or G/Y, G/T and T/T or T/Y.

Practical value of this test

This test is especially useful for breeders because X-linked inheritance can produce affected male puppies when carrier females remain unnoticed. The result helps identify carriers, avoid high-risk matings and protect puppies, buyers and breeding lines.

• Identifies clear dogs, female carriers and genetically affected dogs.
• Helps prevent carrier females from producing affected males.
• Supports transparent communication about inherited muscle health in the breed.
• Enables targeted family and line screening after a positive or suspicious result.