SOD1 and cerebellar ataxia: Our cohort presents some peculiar features, including extreme heterogeneity of clinical manifestations (ataxia with cognitive impairment and ALS) in family members harboring the same variation in SOD1, disease onset with extra-motor symptoms, and presence of a mutation in both heterozygous and homozygous state in the same family, and the latter was associated with an earlier age at onset and a more aggressive disease course (30).