Description: Laryngeal paralysis associated with generalized polyneuropathy (LPPN) is most common in geriatric dogs of various large and giant breeds. Impaired physical performance, coordination of the gait movements, difficulty swallowing, breathing, and an increased risk of respiratory pneumonia are observed in affected dogs. Breathing problems are caused by atrophy of the internal laryngeal muscles leading to the movement restricts of the laryngeal cartilage, which controls the flow of air to and from the trachea during respiration. A change in voice or a noticeable whistling or a hoarse sound may also occur.
Whole-genome association studies, haplotype analysis, and sequencing have identified a missense variant in the CNTNAP1 gene that encodes a contactin-associated protein important for the organization of myelinated axons. CNTNAP1 is essential for the formation of paranodal axoglial connections in the myelinated axons and is also involved in the regulation of the neural progenitor cells and cortical development. This mutation causes insufficient myelination of the nerve fibers and their degeneration. Pathological variants in the CNTNAP1 gene can lead to defective or missing proteins critical for the development of the central or peripheral nervous system.
The age of onset of the disease is variable in predisposed breeds, in the Labradors it ranges on average 4 years before the onset of the age (geriatric) polyneuropathy.
Inheritance: autosomal recessive
Mutation: c.2810G> A (p.Gly937Glu) in CNTNAP1 gene
Sample: EDTA whole blood (1.0 ml) or 2 buccal brushes
The analysis is suitable for the following breeds: Labrador Retriever, Leonberger, Saint Bernard
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