Background and purpose: A novel presenilin1 (PSEN1) mutation associated with dementia and spastic paraplegia in a family with five affected individuals is described. The index patient was a 35-year-old man presenting with cognitive decline, behavioural symptoms, dysarthria, and gait disorder due to spasticity.
Methods and results: Genetic analysis revealed a missense mutation Gln223Arg in exon 7. Initial CSF analysis revealed drastically decreased Abeta42 level despite marginally decreased FDG metabolism.
Conclusion: Cerebrospinal fluid biomarker analysis might point towards genetic analysis of PSEN1 in patients with positive family history and age of onset below 60 years.