Glutamic acid codon 864 (GAA) in exon 8 was changed to lysine (AAA) (c.2590G>A, p.E864K) and a loxP site flanked neomycin resistance gene cassette was inserted into intron 8. The neo cassette was removed through subsequent Cre-mediated recombination. The mutation is the equivalent of the same human mutation associated with Wolfram syndrome (WS). (J:342760)