In genetically determined amyotrophic lateral sclerosis forms, the application of antisense oligonucleotides is generally regarded as a promising potential treatment option which is currently evaluated in clinical studies for various genetic mutations.13 In order to evaluate therapeutic effects of C9orf72-specific approaches, it is essential to characterize the clinical phenotypes and disease courses of affected patients as accurately as possible. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.