How network-based approaches can complement gene identification studies in frontotemporal dementia

Frontotemporal dementia (FTD) is a primary cause of dementia encompassing a broad range of clinical phenotypes and cellular pathologies. Genetic discoveries in FTD have largely been driven by linkage studies in well-documented extended families, explaining most of the patients with a known pathogenic mutation. In the context of complex diseases, it is hypothesized that mutations with reduced penetrance or a combination of low-effect size variants with environmental factors drive disease. Furthermore, these genes are likely to be part of the interaction networks of known FTD genes, contributing to converging cellular processes. In this review, we examine gene discovery approaches in FTD and introduce network biology concepts as tools to assist gene identification studies in genetically complex disease.