We report a 69-year-old woman of Mexican origin with a 6-year history of progressive
paresis, mild
peripheral neuropathy, and recent onset of fluctuating mental status. Head and spinal MRI revealed contrast enhancing thickened meninges which on biopsy disclosed
amyloid deposition. Immunohistochemistry identified the
amyloid as
transthyretin (TTR), and polymerase chain reaction/restriction fragment length polymorphism analysis of blood revealed a Val30Met mutation in one of her TTR genes. This mutation causes familial (hereditary) amyloidotic
polyneuropathy of the Portuguese type (FAP 1). However, unlike FAP 1, in which
peripheral neuropathy is a dominant feature, our patient's clinical manifestations, which included
communicating hydrocephalus and
myelopathy, were more suggestive of familial oculoleptomeningeal
amyloidosis (FOLMA). In summary, the clinical presentation of
TTR Met 30 mutation is more varied than previously suspected, and leptomeningeal
amyloidosis should be considered in the differential diagnosis of obscure conditions involving meninges.