Episodic Falling Syndrome

 

Gene: BCAN

Transmission: Autosomal recessive

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Deletion, BCAN gene; 15.7kb del. exons1,2,3

Medical systems: Neurological, neuromuscular

Breeds: American Cocker Spaniel, Cavalier King Charles Spaniel, Golden Retriever, Pug, Shih Tzu

Age of onset of symptoms: 3 months to four years

Episodic falling syndrome is a hereditary condition seen in the Cavalier King Charles breed of dog.  It involves sudden onset episodes of hypertonicity (rigidity) of the limbs that can be triggered by environmental stimuli including excitement, stress or exercise.  The dog experiencing such an episode assumes a stiff-legged stance, will have difficulty walking (“bunny-hop”) and can fall over.  During episodes, the dog remains fully conscious and there is no pain involved.  Episodes can last for several seconds to up to 5 minutes and will vary in frequency and severity.

 

References:

OMIA link: [1592-9615]

Donner J, Freyer J, Davison S, et al. (2023) Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs.  PLoS Genet. 19(2):e1010651. [pubmed/36848397]

Santifort KM, Mandigers PJJ. (2022) Dystonia in veterinary neurology. J Vet Intern Med 36:1872-1881. [pubmed/36086931]

Lowrie M, Garosi L. (2017) Classification of involuntary movements in dogs: Paroxysmal dyskines

Forman OP, Penderis J, Hartley C, Layward LJ, et al. (2012) Parallel mapping and simultaneous sequencing reveals deletions in BCAN and FAM83H associated with discrete inherited disorders in a domestic dog breed. POoS Genetics 8(1): e1002462. [pubmed/22253609]

Gill JL, Tsai KL, Krey C, Noorai RE, et al. (2012) A canine BCAN microdeletion associated with episodic falling syndrome. Neurobiology of Disease 45: 130-136. [pubmed/21821125]