Deafness and Vestibular Dysfunction (DINGS2), (Discovered in Doberman Pinscher)

Deafness and Vestibular Dysfunction (DINGS2) is an inherited neurological disorder associated with a variant in the MYO7A gene, resulting in defective myosin VIIa protein. Myosin VIIa is important for cochlear hair cell cilia formation and function, and the defect results in abnormal cilia mechanics and decreased impulse transduction. However, it is unclear how this protein defect results in an abnormal vestibular labyrinth. Affected dogs with the MYO7A gene variant typically show bilateral signs within the first few weeks of life which range from mild to severe and can be progressive. Uncoordinated walking, falling, side-to-side or "bobbing" head movements, and variable head tilting may be seen as early as when an affected puppy is beginning to walk. Very young puppies may cry inconsolably, have trouble locating a teat to nurse, or be pushed away by their mother. Puppies may also demonstrate postrotary nystagmus while lacking a vestibulo-ocular reflex. Other vestibular symptoms may include vertigo, dizziness and problems with physical orientation. Brainstem auditory evoked response (BAER) testing usually reflects sensorineural hearing loss. Some vestibular signs may improve with age, although deafness will be permanent and many puppies are euthanized due to severity of signs. It's important to note that one study reported a heterozygote (an individual with 1 copy of the variant) demonstrated deafness without vestibular deficits while another heterozygote had vestibular deficits without deafness, suggesting undiscovered modifying genes may play a role in expression of the disorder.

There is no curative treatment for this condition. Affected puppies should be monitored to assess welfare and supportive care needs. Mildly affected dogs may have relatively normal lives with owners who can accommodate their deafness and neurologic status, including protecting against injury due to vestibular signs. And owners often find it helpful to train an affected dog by using visual cues. However, more severely affected individuals are often euthanized for welfare reasons.

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disorder is autosomal recessive, meaning two copies of the variant are needed for a dog to be at an elevated risk for being diagnosed with the condition. A carrier dog with one copy of the Deafness and Vestibular Dysfunction (DINGS2), (Discovered in Doberman Pinscher) variant can be safely bred with a clear dog with no copies of the Deafness and Vestibular Dysfunction (DINGS2), (Discovered in Doberman Pinscher) variant. About half of the puppies will have one copy (carriers) and half will have no copies of the variant. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. However, given the carrier rate of the variant in the Doberman Pinscher population, there is importance for keeping healthy carriers in the breeding program by breeding them to dogs that tested clear (zero copies) of the associated variant. Please note: It is possible that disorder signs similar to the ones caused by the DINGS2 (MYO7A gene) variant could develop due to a different genetic or clinical cause.