In this study, we aimed to identify p.R148X mutation in <i>NDRG1</i> gene and p.R1109X mutation in <i>SH3TC2</i> gene (responsible for CMT4D and CMT4C, respectively) and to investigate other possible nucleotide changes in exon 14 of <i>SH3TC2</i> gene and exon 7 of <i>NDRG1</i> gene in an Iranian population.<h4>Materials & methods</h4>A total of 24 CMT4D patients, who were referred to Iran Special Medical Center, were clinically and electrophysiologically evaluated in this study. The gene discussed is NDRG1; the disease is Charcot-Marie-Tooth disease type 4D.