In a familial amyotrophic lateral sclerosis (FALS) with SOD-1 mutation (Asn 86-Ser), there were intra-familial clinical diversities. The proband, a daughter patient, shows a mild clinical course of 16 years. Her father died of respiratory failure in 3 years. His initial symptom was weakness of upper extremity. The daughter's first symptom was that of lower extremities. Her respiratory-assist started after 9 years from the onset. She is alive under whole-day respiratory assist while she had been taking nutrients per os for 15 years. Her abilities of swallowing remain, even more dependent of tube-feeding (15 years after the onset). The fact of the presence of intra-familial clinical varieties with SOD-1 mutation in FALS suggests that the mutation is not an exclusive factor to determine the clinical phenotype, age of the onset and rapidity of illness of FALS associated with SOD-1 mutation. We collect reports of FALS with SOD-1 mutation which have similar diversities of intra-familial clinical manifestations as our family. Varieties of intra-familial clinical manifestations of motor neuron disease are shown in 9 families with SOD-1 mutation. The genetic error appears to have a limit, and is not a exclusive cause of FALS. However, we should not underestimate the significance of the discovery of a gene, since it might offer a clue to still unanswered riddle of ALS pathogenesis.