Facial onset amyotrophic lateral sclerosis with K3E variant in the Cu/Zn superoxide dismutase gene

We describe a 48-year-old man, suffering from difficulties in closing his eyes. He subsequently experienced progressive weakness in the facial and bulbar regions and upper limbs. His father and paternal grandmother had limb weakness as initial manifestations and were diagnosed with amyotrophic lateral sclerosis (ALS). In the present case, neuroimaging and laboratory studies were unremarkable, and neurophysiological studies disclosed diffuse denervation. Genetic testing identified a heterozygous c.10A>G, p.K4E (K3E) variant in superoxide dismutase 1 (SOD1) gene, and he was diagnosed with familial ALS. In ALS, facial muscles are rarely involved as an initial symptom. The present patient is a first case of facial onset ALS with K3E variant in SOD1 gene. Two case reports identified facial palsy as an initial manifestation in familial ALS with C6G variant in SOD1 gene. Several ALS patients with variants in SOD1 gene may have facial onset history.