Glutamic acid codon 196 (GAG) in exon 5 was changed to lysine (AAG) (p.E196K) and a loxP site flanked neomycin resistance gene cassette was inserted into intron 5 using BAC RP23-57A20 with recombineering. The neo cassette was removed through subsequent cre-mediated recombination. The mutation is associated with dominant intermediate Charcot-Marie-Tooth (CMT) disease type C (CMTC) in humans.