A form of spinocerebellar ataxia, a clinically and genetically heterogeneous group of cerebellar disorders due to degeneration of the cerebellum with variable involvement of the brainstem and spinal cord. SCAN3 is an autosomal recessive disorder characterized by onset in the first decade of slowly progressive distal muscle weakness and atrophy
 and distal sensory impairment due to an axonal peripheral neuropathy. Affected individuals have gait disturbances and sometimes manual dexterity difficulties, as well as cerebellar ataxia associated with cerebellar atrophy on brain imaging. The disease is spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 3 (Experimental Factor Ontology id EFO_0010249).