Affected gene: RNF170
Mode of inheritance: Autosomal recessive
Mutation: U_Cfam_GSD_1.0 chr16 g.23653872delG
OMIA reference: 002876-9615
Applicable breed for testing: Miniature American Shepherd
Description and clinical signs
A genetic variant of the RNF170 gene associated with neuroaxonal dystrophy (NAD) has been identified in the Miniature American Shepherd. The first clinical signs typically appear around two years of age.
Affected dogs develop progressive weakness and coordination deficits of the hind limbs, which may progress to partial bilateral paralysis. Slowly progressive myelopathy is observed, primarily affecting the thoracic and lumbar spinal segments. In some cases, the cervical spine, cerebellum, or forebrain may also be involved.
Affected dogs do not typically exhibit pain or balance disorders. Gait abnormalities are generally more pronounced during walking than running. The progressive nature of the condition leads to a decline in quality of life; however, lifespan is not significantly reduced in itself.i.

References:
Correction to "Canine RNF170 Single Base Deletion in a Naturally Occurring Model for Human Neuroaxonal Dystrophy". Mov Disord 40:393, 2024. Pubmed reference: 39648631. DOI: 10.1002/mds.30079. 
Cook, S.R., Schwarz, C., Guevar, J., Assenmacher, C.A., Sheehy, M., Fanzone, N., Church, M.E., Murgiano, L., Casal, M.L., Jagannathan, V., Gutierrez-Quintana, R., Lowrie, M., Steffen, F., Leeb, T., Ekenstedt, K.J.: Canine RNF170 single base deletion in a naturally occurring model for human neuroaxonal dystrophy. Mov Disord 39:2049-2057, 2024. Pubmed reference: 39177409. DOI: 10.1002/mds.29977.