A novel PSEN1 mutation in a patient with sporadic early-onset Alzheimer's disease and prominent cerebellar ataxia.

PSEN1 gene mutations represent the first cause of familiar early-onset Alzheimer's disease (EOAD). More than 190 mutations in PSEN1 have been reported to date. The clinical phenotype is mainly characterized by cognitive decline but movement disorders have been rarely described. We report a novel PSEN1 mutation (p.Thr147Pro) responsible for a sporadic early-onset dementia with prominent cerebellar symptoms, resembling a spinocerebellar syndrome. Neuroradiological and cerebrospinal fluid biomarkers examinations were performed on the patient, showing typical findings of EOAD and suggesting the pathogenicity of the novel mutation. Our study widens the number of unusual phenotypes related to PSEN1 mutations.