A 52-year-old man had leg weakness for 6 months and no family history for SCA3. His mother had diabetes mellitus and died at 86 years. His father's age of death and details were unknown. The facial and cranial nerves were normal. He had distal lower limb weakness. Arm reflexes were sluggish, the knee jerks were brisk, ankle jerks were absent, and plantar responses were mute. Results of the sensory examination were unremarkable. Results of the following tests were either negative or normal: complete blood cell count, erythrocyte sedimentation rate, liver and thyroid function, VDRL, human T-lymphotrophic virus 1, serum protein electrophoresis, rheumatoid factor, antinuclear antibody, Kveim, chest radiograph, and levels of glucose, urea, electrolytes, vitamin B12, folate, extractable nuclear antigen, antineutrophil cytoplasmic antibody, and cerebrospinal fluid. Electrophysiology showed absent (medians, ulnars, and surals) or small (radial, 4.6 μV) sensory nerve action potentials, absent soleus H-reflexes, normal motor conduction velocities and F-wave latencies (medians, ulnars, and common peroneal nerves), no conduction block, small lower limb compound muscle action potentials, and distal denervation in the upper and lower limbs consistent with an axonal sensorimotor polyneuropathy.