[Familial Alzheimer's disease with presenilin 2 N141I mutation. A case report]

Alzheimer's disease (AD) is the most common form of dementia. Approximately 0.5 per cent of all AD is caused by single major gene mutations and autosomal dominant inheritance. These familial types with early-onset (EOFAD) usually display dementia before the age of 60. Such mutations have been found in the gene encoding amyloid precursor protein (APP), and in the genes encoding presenilin 1 (PSEN1) or presenilin 2 (PSEN2). We herein report the case of a German patient with a EOFAD and a missense mutation at codon 141 (N141I) of the PSEN2 gene. The patient came to our psychiatric clinic for the first time when she was 49 years old. During the following 3 years, her Mini-Mental-State-Examination (MMSE) score dropped from 14 to 0 points. Positron emission tomography with [18F] Fluorodeoxyglucose (18F-FDG PET) demonstrated glucose reduction left parietal and in the pre-cuneus region. Follow-up 18F-FDG PET studies showed progressive hypometabolism of both temporoparietal lobes and left frontal lobe.