Representation of C9orf72RE as a social cognition genetic endophenotype

Genetic endophenotypes mark the onset, clinical characteristics and disease severity in neurodegenerative diseases. The C9orf72 hexanucleotide repeat expansion (C9orf72RE) is the most common genetic cause of behavioural variant of frontal–temporal dementia (bvFTD). Dysfunctions in executive processes and social cognition represent the core symptoms of bvFTD, essential for clinical diagnosis. The presence of an extensive symptomatic overlap with psychiatric disorders, particularly for impaired social cognition is responsible for frequent misdiagnosis in the early phase of disease. Of relevance, bvFTD and psychiatric brain disorders share involvement of frontal–subcortical neuronal circuits, as confirmed by functional imaging studies.1 It is conceivable that C9orf72RE, and …