The goal of this observational study is to understand the clinical variability in a population of ALS patients using multidimensional biomarkers. The main questions it aims to answer are: * Which set of biomarkers explain genotypic-phenotypic correlations in ALS? * Which set of biomarkers can be used to subdivide the ALS population in homogeneous subgroups? Participants will undergo: * neurological evaluation * neurophysiological evaluation * neuropsychological evaluation * whole exome sequencing * biomarker measurement in CSF and plasma