A Case of Early-Onset VCP-Related Frontotemporal Dementia: Insights from Neuroimaging and Genetic Analysis.

Objectives: Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by focal neuronal loss in the frontal and temporal cortices. Although microtubule-associated protein tau, granulin, and C9orf72 mutations are common in behavioral variant FTD (bvFTD), there are also less common variants. This case highlights a 48-year-old man with a diagnosis of bvFTD with valosin-containing protein (VCP) mutation based on comprehensive clinical, genetic, and neuroimaging findings. Methods: The patient underwent neurological, psychiatric, and neuropsychological assessments, along with magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging using 18F-FDG. Whole genome sequencing was performed to identify potential pathogenic variants. Results: The patient exhibited severe neurobehavioral symptoms, including paranoia, emotional disconnection, and cognitive decline, ultimately leading to suicide. Although MRI findings were unremarkable, PET imaging revealed regional lower glucose metabolism (range from -1.7% to -16.5%). Whole genome sequencing identified a pathogenic VCP mutation (NM_001354927). Conclusions: This case highlights a well-documented case of VCP-related bvFTD and the utility of advanced and novel PET imaging in identifying functional deficits despite normal structural MRI. Integrating genetic testing and neuroimaging is crucial for accurate diagnosis and better understanding of genotype-phenotype correlations in rare FTD variants.