Incidence of pathogenic, likely pathogenic, and uncertain ALS variants in a clinic cohort.

Our data suggest that the incidence of P and LP variants in genes other than C9orf72 is lower than expected in Midwestern fALS cases compared with research cohorts and highlights the challenge of variant interpretation in ALS. An accurate understanding of the incidence of pathogenic variants in clinic-based ALS populations is necessary to prioritize targets for therapeutic intervention and inform clinical trial design.