[Case report of transthyretin Val30Met familial amyloid polyneuropathy presenting hydrocephalus].

A 70-year-old man was admitted to our hospital with visual loss, dysesthesia, gait disturbance, and urinary retention. A pacemaker was implanted 1 year ago for atrioventricular conduction block. Neurologic examination revealed mild cognitive impairment, near blindness with vitreous opacity, diffuse muscle weakness, loss of all sensory modalities with areflexia, and orthostatic hypotension. Head CT showed hydrocephalus. The Congo red staining of vitrectomized specimen and the biopsied sural nerve showed amyloid depositions. Gene analysis disclosed Val30Met missense mutation of transthyretin, which is responsible for familial amyloid polyneuropathy. His bed-ridden brother also had severe urinary dysfunction and orthostatic hypotension with hydrocephalus on MRI. These two sibling cases suggest correlation of the transthyretin Val30Met mutation with hydrocephalus, a rare phenotype of this disease.