While mostly a sporadic disease, approximately 10% of amyotrophic lateral sclerosis (ALS) cases are familial. ALS I can exhibit autosomal dominant or recessive inheritance. Patients have reduced levels of superoxide dismutase-1 (SOD1). Germline mutations in the SOD1 gene are associated with developing ALS1; mutations in the ANG, NEFH, PRPH, and DCTN1 are associated with susceptibility. OMIM: 105400