An N98S (AAC>AGC) mutation was inserted in exon 1 and a floxed neo cassette was inserted in intron 1 via homologous recombination. Cre mediated recombination removed the neo cassette. Protein levels are decreased approximately 30% in the brains and spinal cords of heterozygous mice compared to wild-type controls. Protein levels in the sciatic nerves of heterozygous mice are decreased ~80% compared to wild-type controls. (J:220605)