The following genes established to cause familial ALS and those that were commercially available at that time were tested and did not reveal any pathogenic mutations: superoxide dismutase type 1, TAR DNA-binding protein, angiogenin, FIG4 phosphoinositide 5-phosphatase, and fused in sarcoma (FUS) RNA-binding protein. A magnetic resonance imaging of his lumbosacral spine disclosed no significant abnormalities that could account for his symptoms. The gene discussed is FUS; the disease is amyotrophic lateral sclerosis.