Hereditary cerebral hemorrhage with amyloidosis associated with the E693K mutation of APP.

Objective: To report the clinical, genetic, neuroimaging, and neuropathologic studies of patients with the hereditary cerebral hemorrhage with amyloidosis linked to the APP E693K mutation.
Design: Case series. Clinical details and laboratory results were collected by direct evaluation and previous medical records. DNA analysis was carried out in several affected subjects and healthy individuals. Neuropathologic examination was performed in 2 subjects.
Setting: Southern Lombardy, Italy. Patients Individuals with and without amyloidosis in 4 unrelated Italian families (N = 37). Main Outcome Measure Genotype-phenotype relationship.
Results: The affected individuals presented with recurrent headache and multiple strokes, followed by epilepsy and cognitive decline in most of them. The disease was inherited with an autosomal dominant trait and segregated with the APP E693K mutation. Neuroimaging demonstrated small to large hematomas, subarachnoid bleeding, scars with hemosiderin deposits, small infarcts, and leukoaraiosis. Amyloid-beta immunoreactivity was detected in the wall of leptomeningeal and parenchymal vessels and in the neuropil, whereas phosphorylated tau, neurofibrillary changes, and neuritic plaques were absent.
Conclusions: These findings expand the number of APP mutations linked to hereditary cerebral hemorrhage with amyloidosis, reinforcing the link between this phenotype and codon 693 of APP.