Amyotrophic Lateral Sclerosis Genetic Access Program: Paving the Way for Genetic Characterization of ALS in the Clinic.

Objective: To report the frequency of amyotrophic lateral sclerosis (ALS) genetic variants in a nationwide cohort of clinic-based patients with ALS with a family history of ALS (fALS), dementia (dALS), or both ALS and dementia (fALS/dALS).

Methods: A multicenter, prospective cohort of 573 patients with fALS, dALS, or fALS/dALS, underwent genetic testing in the ALS Genetic Access Program (ALS GAP), a clinical program for clinics of the Northeast ALS Consortium. Patients with dALS underwent hexanucleotide repeat expansion (HRE) testing; those with fALS or fALS/dALS underwent HRE testing, followed by sequencing of , , , , and .