Deafness, non syndromic

Gene: LOXHD1

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: Substitution, LOXHD1 gene; c.5747 G>C, p.(G1914A)

Medical system: Auditory

Breeds: American Staffordshire Terrier/Amstaff, Rottweiler

Age of onset of symptoms:  congenital or several weeks after birth.

Deafness in dogs is a common disorder, and can have hereditary (genetic) or environmental causes.  Although over a hundred gene mutations have been implicated in the genetics of hearing loss in humans, the transfer of this knowledge to deafness in the dog has been slow.   From human and mouse studies the LOXHD1 gene is known to be involved in cochlear hair cell function, and mutations within this gene can result in sensorineural bilateral deafness due to degeneration of cochlear hair cells.  Deafness was noted within a litter of Rottweiler puppies, and molecular studies identified a mutation within the LOXHD1 gene as being responsible.  Clinically, the affected animals were unreactive to noise and showed no  response to brainstem auditory evoked response (BAER) testing.  The deafness was non-syndromic in that it was the only congenital anomaly observed.  DNA tests are now available for detecting the mutation.  DNA tests are now available to detect the mutation and eliminate the disease from the breed.

References:

OMIA link: [2336-9615]

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]

Hytönen MK, Niskanen JE, Arumilli M, et al. (2021) Missense variant in LOXHD1 is associated with canine nonsyndromic hearing loss. Hum Genet 140:1611-18. [pubmed/33983508]

Strain GM. (2015) The genetics of deafness in domestic animals.  Front Vet Sci 2:29. [pubmed/26664958]

Coppens AG, Kiss R, Heizmann CW, et al. (2001) An original inner ear neuroepithelial degeneration in a deaf Rottweiler puppy. Hear Res 161:65-71. [pubmed/11744282]

Contributed by:  Malory Lacroix, Ariane Lalande, Jennifer Liu and Katherine Schunk, class of 2027, Veterinary Medicine Faculty, University of Montreal.  (Translation: DWS).