CRISPR/Cas9 technology generated a G to A change at position 181 resulting in an aspartate to asparagine substitution at amino acid 61 (p.D61N). In addition, a silent A to G change at position 168 and a silent A to T conversion at position 177 were introduced to prevent gRNA binding and recleavage and to eliminate a Ddel restriction enzyme site, respectively. This mutation is predicted to generate a new N-glycosylation site and causes a severe early-onset form of Charcot-Marie-Tooth type IB neuropathy in humans. (J:335549)