The human SETX cDNA containing an arginine to histidine substitution at amino acid 2136 (R2136H; c.6407G>A) is under the control of the mouse prion promoter. The R2136H mutation is one of two identified to date in individuals with amyotrophic lateral sclerosis type 4 (ALS4). Two lines were established: 1917 and 1920. Line 1920 shows expression of the transgene at approximately 2.5X that of the endogenous mouse gene.