[Hereditary sensory and autonomic neuropathy 1E showing hyperreflexia: a case report].

A 52-year-old man had developed hearing loss since childhood, as well as recurrent foot ulcers and osteomyelitis since his forties. He presented with gait disturbance and dysarthria that had worsened over four years and a month, respectively. Neurological exams revealed cognitive impairment, proximal weakness of the lower extremities, generalized hyperrflexia, ataxia, sensory disturbances predominant in deep sensation, urinary retention, and gait instability. On nerve conduction study, no sensory nerve action potentials were evoked in the upper and lower limbs. Since his grandmother suffered from similar symptoms, we investigated genetic analysis, which revealed a missense mutation (c.1483T>C, p.Y495H) in DNA methyltransferase 1 gene. He was subsequently diagnosed with hereditary sensory and autonomic neuropathy 1E (HSAN1E). It is important to recognize that increased deep tendon reflex can be observed in HSAN1E.