In some cases, these patients are initially misdiagnosed with amyotrophic lateral sclerosis (ALS; Lou Gehrig’s disease), however, genetic testing for an expanded AR CAG repeat (n ≥ 38) confirms a diagnosis of SBMA (Parboosingh et al., 1997; Bruson et al., 2012). This evidence concerns the gene AR and amyotrophic lateral sclerosis.