Any amyotrophic lateral sclerosis in which the cause of the disease is a mutation in the ALS2 gene. The disease is amyotrophic lateral sclerosis type 2, juvenile (Monarch Disease Ontology term MONDO_0008780). Also known as: ALS2, ALS2 amyotrophic lateral sclerosis, amyotrophic lateral sclerosis 2, amyotrophic lateral sclerosis 2, juvenile, amyotrophic lateral sclerosis caused by mutation in ALS2.