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References OMIM Gene GeneReviews HGMD HGNC
last update : 05-02-2015
Symbol FBD
Location 13q14.3
Name dementia, familial British
Other name(s)
  • cerebral amyloid angiopathy, British type
  • presenile dementia with spastic ataxia
  • Corresponding gene ITM2B
    Main clinical features
  • characterized by progressive dementia, spasticity, cerebellar ataxia with onset at around the fifth decade of life and cerebral amyloid angiopathy, non neuritic and perivascular plaques and neurofibrillary tangles as predominant pathological lesions
  • onset occurred between 40 and 60 years of age with early onset of spasticity with increased deep tendon reflexes and tone
  • MRI demonstrated extensive alteration of signal intensity in periventricular white matter, with sparing of U fibers, as well as abnormal signal intensity in brainstem and cerebellar white matter
  • Genetic determination
    Function/system disorder psychiatric disorder
    Type disease
    Gene product
    Name ITM2B
    Gene mutationChromosome rearrangementEffectComments
    various types   truncated protein mutation at the stop codon resulting in a longer open reading frame releasing a 4kb Abri amyloid subunit (in Danish patients)