Deafness with Vestibular Dysfunction (DVD), aka DINGS
In Doberman Pinschers, a neurological disorder causing deafness and balance/coordination issues, commonly referred to as DINGS, is associated with variants in two different genes. One appears to result in deafness in one ear while the other shows deafness in both ears.
Phenotype: Deafness in one or both ears often accompanied by a loss of balance, head “bobble” and tilt.
Mode of Inheritance:Autosomal recessive
Alleles:N = Normal, DINGS1 = unilateral deafness with vestibular dysfunction, DINGS2 = bilateral deafness with vestibular dysfunction
Breeds appropriate for testing: Doberman Pinscher
Explanation of Results:
Dogs with N/N genotype do not have the Doberman Pinscher deafness variant.
Dogs with N/DINGS1 genotype are carriers of Doberman Pinscher deafness but are unaffected. If two carriers are mated, 25% of the offspring in the litter are expected to be affected and another 50% of the offspring are expected to be carriers.
Dogs with N/DINGS2 genotype are carriers of Doberman Pinscher bilateral deafness but are unaffected. If two carriers are mated, 25% of the offspring in the litter are expected to be affected and another 50% of the offspring are expected to be carriers.
Dogs with DINGS1/DINGS1 genotype will display deafness in at least one ear and may exhibit balance/coordination issues.
Dogs with DINGS2/DINGS2 genotype will display deafness in both ears and may exhibit balance/coordination issues.
At least 15 business days; may be delayed beyond 15 business days if sample requires additional testing, or a new sample is requested.
Deafness with vestibular dysfunction, or DINGS, is a neurological disorder resulting from improper development of the inner ear. This includes both the cochlea (the part of the inner ear that produces nerve impulses in response to sound vibrations) as well as the vestibular labyrinth (the elaborate set of interconnected canals of the inner ear assisting with balance, among other functions). In affected dogs, improper development of the cochlea prevents proper transmission and amplification of sounds from the ear to the brain. The vestibular labyrinth, which is directly connected to the cochlea, provides information regarding motion, spatial orientation, and head position to the brain. An affected dog may have vertigo, dizziness, balance issues as well as spatial orientation issues. Symptoms can present as mild to severe, but are early onset and can be progressive. A BAER hearing test from your veterinarian can provide more information as to the degree of deafness and vestibular impact.
A frameshift variant in the protein tyrosine phosphatase, receptor type Q (PTPRQ: c.5909insA ,p.N1970Lfster24) gene was determined to be associated with unilateral deafness and vestibular response in an affected pup. PTPRQ has been hypothesized to promote long-term survival of the hair cells as well as maturation of the hair bundles within the cochlea. 2.97% of Dobermans were identified as carriers of this allele.
A second variant associated with bilateral deafness and vestibular response was identified in a different gene, specifically MYO7A (c.3719G>A, p.R1240Q). This missense variant is predicted to change a highly conserved amino acid, likely impacting its function in sensory neuroepithelial cells. Of the 309 known human MYO7A mutations, all are associated with some degree of hearing impairment, and 261 have associated balance issues. The presence of this allele was identified in 10% of Dobermans.
In Doberman Pinschers, both DINGS variants are inherited in an autosomal recessive fashion. For each variant, two copies must be present for the disease to manifest, and both sexes are affected equally.
Testing for these variants can assist veterinarians with diagnosis of DINGS and helps breeders identify carriers among breeding stock to select appropriate mates that will reduce the risk of producing affected offspring. To avoid the possibility of producing affected puppies, matings between known carriers for either variant is not recommended.
Note: These tests are specific for the autosomal recessive variants present in the Doberman Pinscher.
Normal. Dog does not have the variant associated with unilateral deafness.
Carrier. Dog has one copy of the variant associated with unilateral deafness.
Affected. Dog has two copies of the variant associated with unilateral deafness and is expected to develop deafness possibly with vestibular response.
Deafness with Vestibular Dysfunction (DINGS 2)
Normal. Dog does not have the variant associated with bilateral deafness.
Carrier. Dog has one copy of the variant associated with bilateral deafness.
Affected. Dog has two copies of the variant associated with bilateral deafness and is expected to develop deafness possibly with vestibular response.
Wilkes, M.K., & Palmer, A.C. (1992). Congenital deafness and vestibular deficit in the dobermann. Journal of Small Animal Practice, 33(5), 218-224. doi: 10.1111/j.1748-5827.1992.tb01120.x
Guevar, J., Olby, N.J., Meurs, K.M., Yost, O.L., & Friedenberg, S.G. (2018). Deafness and vestibular dysfunction in a Doberman Pinscher puppy associated with a mutation in the PTPRQ gene. Journal of Veterinary Internal Medicine, 32(2), 665 - 669. doi: 10.1111/jvim.15060
Webb, A.A., Ruhe, A.L., & Neff, M.W. (2019). A missense mutation in MYO7A is associated with bilateral deafness and vestibular dysfunction in the Doberman pinscher breed. Canadian Journal of Veterinary Research, 83(2), 142-148. PMID: 31097876