The purpose of this study is to learn more about amyotrophic lateral sclerosis (ALS) and other related neurodegenerative diseases, including frontotemporal dementia (FTD), primary lateral sclerosis (PLS), hereditary spastic paraplegia (HSP), progressive muscular atrophy (PMA) and multisystem proteinopathy (MSP). More precisely, we want to identify the links that exist between …