Therefore, we detected rare KIF1A variants in 1,068 ALS patients, comprising 988 sporadic and 80 familial cases, using whole-exome sequencing (WES), and analyzed the genotype–phenotype relationship in patients with KIF1A variants, deepening our understanding of how KIF1A deficiency affects ALS pathogenesis. The gene discussed is KIF1A; the disease is amyotrophic lateral sclerosis.