Very early-onset behavioral variant frontotemporal dementia in a patient with a variant of uncertain significance of a FUS gene mutation.

The behavioral variant of Frontotemporal dementia (bvFTD) has typically a progressive course with cognitive and behavioral changes that manifests between 50 and 70 years. Very early-onset bvFTD with rapid progression is a rare syndrome under the frontotemporal lobar degeneration (FTLD) umbrella that has been associated with a variety of protein deposition and genetic mutations. We present a case of a 24-year-old man who developed behavioral symptoms and progressed with severe cognitive impairment and functional loss within months.   Genetic testing identified a variant of uncertain significance (VUS) mutation in the FUS gene.