Hereditary Cerebral Amyloid Angiopathy Associated with a Novel Amyloid Beta Precursor Protein Mutation

The cerebrovascular deposition of amyloid fibrils, particularly in the walls of leptomeningeal and cortical arteries and arterioles, is a well-recognized cause of primary intracerebral hemorrahagic stroke, ischemic lesions and dementia. The amyloid beta peptides (Aß) peptide is the amyloid subunit in most forms of cerebral amyloid angiopathy (CAA), including age-related CAA and CAA associated with sporadic and familial Alzheimer’s disease. Missense mutations within the Aß sequence of the amyloid-beta precursor protein gene (AßPP) cause autosomal dominant, presenile cerebral amyloid angiopathy in families with different ethnic background. Neuropathological examination was performed on paraffin-embedded brain tissue obtained at autopsy from two family members. Postmortem examination demonstrated in both patients the presence of vascular amyloid deposits in leptomeningeal and cortical vessels of cerebral lobes. Immunoelectron microscopy characterization of amyloid fibrils in the walls of affected vessel showed specific immunostaining with both anti-Aß40 and anti-Aß42 antibodies.