PIK3CA and Charcot-Marie-Tooth disease: Notably, the presence of the PIK3CA (H1047R) mutation was more prominent in benign CMT and grade I malignant CMT cases (22 out of 53 cases, 41.5%) compared to grade II and III malignant CMT cases (4 out of 27 cases, 14.8%) (Chi-square test, P = 0.016) (Table 1).