A presenilin-1 mutation in a Japanese family with Alzheimer's disease and distinctive abnormalities on cranial MRI

Some patients with familial Alzheimer's disease (FAD) have mutations in the presenilin-1 (PS-1) gene on chromosome 14. We report a Japanese family with AD an Ala285Val substitution in exon 8 of the PS-1 gene. FAD in this family was characterized by relatively late onset (mean age 50 years) absence of myoclonus seizures or paratonia. Levels of tau were markedly elevated in CSF whereas CSF levels of amyloid protein were normal. MRI of the cranium showed marked linear signal abnormalities within white matter in the parieto- occipital lobes consistent with cortical amyloid angiopathy of the type encountered in patients with the PS-1 gene mutation.