UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory

Polyneuropathy with Ocular Abnormalities and Neuronal Vacuolation (POANV)

Polyneuropathy with ocular abnormalities and neuronal vacuolation (POANV) is a hereditary neurologic defect that occurs in Black Russian Terriers and Rottweilers. This disorder has been previously described as juvenile-onset, laryngeal paralysis and polyneuropathy (JLPP) in Black Russian Terriers and neuronal vacuolation and spinocerebellar degeneration (NVSD) in Rottweilers. Signs of disease common to both breeds are early onset (around 3 months of age) of laryngeal paralysis (failure of the voice box to function), microphthalmia (small eyes), congenital cataracts (clouding of the lens of the eye) and axonal peripheral neuropathy (damage of peripheral nerves in muscle, skin) that presents as pelvic limb weakness and motor deficits. The disease is progressive and affected animals either die or are euthanized for steadily decreasing quality of life by 1 year of age.

POANV results from a nucleotide deletion (c.743delC) in the RAB3GAP1 gene (c.743delC), reported here as P. The disease is inherited in an autosomal recessive fashion, which means that males and females are equally affected and that two copies of the defective gene are needed to cause POANV. Dogs with one normal and one affected gene (carriers) are normal and show no sign of the disease.

The VGL offers a genetic test for POANV. Test results assist veterinarians with diagnosis of POANV and help breeders to identify carriers to avoid breeding these together. Mating of carriers is expected to produce 25% of affected puppies

Testing is appropriate for:  Black Russian Terriers and Rottweilers.

Allow 3-6 business days for results.

Results reported as:


Normal - no copies of the POANV/JLPP mutation


Carrier - 1 copy of the POANV/JLPP mutation; dog is normal


Affected - 2 copies of the POANV/JLPP mutation; dog will develop polyneuropathy


T. Mhlanga-Mutangadura, G.S. Johnson, R.D. Schnabel, J. F. Taylor, G.C. Johnson, M.L. Katz, G.D. Sheltone, T.E. Lever, E.  Giuliano, N. Granger, J. Shomper, D. P. O'Brien. (2016) A mutation in the Warburg syndrome gene, RAB3GAP1, causes a similar syndrome with polyneuropathy and neuronal vacuolation in Black Russian Terrier dogs. Neurobiology of Disease 86:75-85.

T. Mhlanga-Mutangadura, G.S. Johnson, A. Ashwini, G.D. Shelton, S.A. Winnogle, G.C. Johnson, K. Kuroki, and D.P. O’Brien. (2016) A Homozygous RAB3GAP1;c.743delC mutation in Rottweilers with neuronal vacuolation and spinocerebellar degeneration. J. Vet. Int. Med. 30(3):813-818.

Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL