Diagnostic challenges for genetic approaches in Amyotrophic Lateral Sclerosis

Abstract

Over the past years, our understanding of the genetic mechanisms involved in complex diseases, such as Amyotrophic Lateral Sclerosis, has increased dramatically. ALS is a fatal and devastating motor neuron disease for which there is no truly effective cure. In 1993, the first gene associated with ALS was identified (1). Since then, our knowledge of the genetic mechanisms of disease has expanded significantly. Diagnostic tools have followed these research insights and Sanger DNA sequencing has been routinely used for many years. The emergence of next-generation DNA sequencing (NGS) approaches in the same decade allowed high throughput approaches to DNA sequencing, enabling the identification of new genes and pathways that highlight the heterogeneity of ALS disease, providing exciting opportunities for the identification of biomarkers useful for patient stratification and helping the development of targeted therapies. Despite our increased understanding of the mechanisms of this disease, the majority of patients remain undiagnosed, and the remaining cases have no successful treatments. The absence of an effective cure can be well explained by the complex and heterogeneous nature of ALS, with patients displaying distinct clinical characteristics and distinct molecular mechanisms. In this context, the molecular profiling of patients into clinically meaningful subgroups can be extremely valuable for the development of new precision diagnostics. In this thesis project, we provide an overview on the genetic investigation of ALS patients using different diagnostic approaches highlighting the importance of each methodology and their integrative use for the study of the disease, with the aim of providing a more comprehensive characterization of patients useful for the development of new-targeted strategies in clinical practice and personalized medicine.