A canine BCAN microdeletion associated with episodic falling syndrome

Area of Science:

• Canine Genetics
• Neurology
• Molecular Biology

Background:

• Episodic falling syndrome (EFS) is a neurological disorder in Cavalier King Charles spaniels.
• EFS is characterized by hypertonicity and collapse triggered by stimuli like exercise or stress.

Purpose of the Study:

• To identify the genetic cause of EFS in Cavalier King Charles spaniels.
• To develop diagnostic tools for EFS.

Main Methods:

• Genome-wide association study to locate the EFS locus on canine chromosome 7.
• Prioritization of candidate genes and identification of a BCAN gene deletion.
• Development of Multiplex PCR and MLPA genotyping tests.

Main Results:

• A 15.7 kb deletion in the BCAN gene, encoding brevican, was identified as the causal mutation for EFS.
• Genotyping tests accurately distinguish between normal, carrier, and affected dogs.
• A high carrier frequency (12.9%) was found in US CKCS populations without EFS history.

Conclusions:

• The BCAN microdeletion is the causative mutation for EFS.
• Molecular genetic tests enable diagnosis and carrier screening for EFS.
• These tests facilitate breeding programs to reduce EFS prevalence and aid in affected dog management.