Familial Danish dementia

Familial Danish dementia
Other namesFDD, ADan amyloidosis, Heredopathia ophthalmootoencephalica, HOOE, ITM2B amyloidosis, Cerebellar ataxia, cataract, deafness, and dementia or psychosis
SpecialtyNeurology
SymptomsCataracts, Deafness, Progressive ataxia, Dementia,
Usual onset20-30 years old
CausesMutations of the BRI2 gene
Diagnostic methodFamily history, symptoms, and genetic testing

Familial Danish dementia is an extremely rare, neurodegenerative disease characterized by progressive cataracts, loss of hearing, cerebellar ataxia, paranoid psychosis, and dementia. Neuropathological hallmarks include extensive atrophy of all areas of the brain, chronic diffuse encephalopathy, and the presence of exceedingly thin and nearly totally demyelinated cranial nerves.

FDD is an autosomal dominant disorder caused by a mutation in the BRI2 gene on chromosome 13. FDD is one of the two types of hereditary, cerebral amyloid angiopathy, alongside familial British dementia.