Estimated Prevalence and Incidence of Amyotrophic Lateral Sclerosis and SOD1 and C9orf72 Genetic Variants

The estimated number of patients with SOD1 and C9orf72 ALS suggests that although the proportions of SOD1 and C9orf72 are higher among those with fALS, the majority of SOD1 and C9orf72 ALS cases may be found among those with sALS (about 53 and 74%, respectively). These results suggest that classification of fALS based on reported family history does not capture the full picture of ALS of genetic origin.