A C to T transition at position 892 resulting in an arginine to cysteine substitution at amino acid 298 (p.R298C) was introduced in exon 5 and an loxP-flanked neomycin selection cassette was inserted in intron 5. The selection cassette was removed via cre-mediated recombination. The R298C is the causative homozygous mutation in patients with Charcot-Marie-Tooth disease type 2B1. (J:322912)