ALS2 and juvenile primary lateral sclerosis: Approximatively 100 pathogenic variants in ALS2 have been identified in patients with MNDs [135,136] and cause a number of autosomal recessive juvenile-onset MNDs, including ALS type 2 (ALS2), infantile-onset ascending hereditary spastic paraplegia (IAHSP) and juvenile primary lateral sclerosis (JPLS) [133,134,137].