Some patients have received amyotrophic lateral sclerosis (ALS) or Charcot-Marie-Tooth (CMT) neuropathy as initial diagnoses (4–6), but a gene test of a single heterozygous variant, c.197G>Tp.G66V, in coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10), sets the diagnosis of SMAJ (2). The gene discussed is CHCHD10; the disease is amyotrophic lateral sclerosis.