Spastic paraparesis linked to a rare presenilin-1 mutation.

Familial Alzheimer's disease (FAD) accounts for < 1% of AD cases and is mainly associated with pathogenic variations in presenilin 1 (PSEN1), PSEN2 and the amyloid precursor protein [1]. Most patients present with an earlier onset classic amnestic syndrome [2]. We report a 37-year-old female with progressive spastic paraparesis (SP), wheelchair-dependent at 40-years-old and bedridden at 43yo. She developed mild cognitive complaints at 41yo. Multigene panel revealed a rare probably pathogenic heterozygous PSEN1 variant (p.Pro433Ser). CSF was consistent with pathological Alzheimer continuum. This highlights the importance of considering AD in SP of undetermined cause, showing a novel clinical association between PSEN1 p.Pro433Ser and SP.