This study seeks to systematically evaluate both microstructural (myelin content via MTR) and macrostructural features (nerve cross‐sectional area, or CSA, and shape) of the sciatic nerve within a cohort of patients with PMP22‐related diseases (CMT1A and HNPP) and healthy control subjects. Here, PMP22 is linked to Charcot-Marie-Tooth disease type 1A.