SOD1 and amyotrophic lateral sclerosis: In SBMA, aggregates contain mutant androgen receptors (AR) with an elongated polyglutamine tract (ARpolyQ), while in ALS aggregates contain TDP43, ubiquilin, optineurin, etc. Exceptions are familial ALS (fALS) forms linked to superoxide dismutase 1 (SOD1) mutations, in which aggregates are composed of mutant SOD1.