Myotonia congenita 3 variants (CLCN1-related) - Cat

Myotonia congenita in cats

This genetic test examines three CLCN1 variants that cause myotonia congenita in cats: c.428_433+1del, c.991G>C and c.1930+1G>T. The condition is also known as myotonia, CLCN1-related myotonia or chloride-channel myotonia. Altered ClC-1 channel function makes muscles relax poorly after contraction.

Clinical picture and recognition

Cats with myotonia congenita may show short stiff strides, prominent muscle development, a protruding tongue, drooling, swallowing difficulty and falling after being startled. The cat usually remains alert, but muscle relaxation is abnormally slow.

Why this test is useful

• The test combines three relevant CLCN1 variants in one analysis.
• The result shows whether the cat is clear, a carrier or genetically affected for each variant.
• Breeders can avoid carrier combinations and select deliberately without excluding healthy carriers unnecessarily.

Myotonia congenita is inherited as autosomal recessive: two copies of the same disease-causing variant cause the condition.