De novo MFN2 mutations are regularly found in patients with a classical CMT2 phenotype (Østern et al., 2013), and some MFN2 mutations have also been reported as de novo in several patients (Züchner et al., 2004; Chung et al., 2006; Verhoeven et al., 2006; Cho et al., 2007). This evidence concerns the gene MFN2 and Charcot-Marie-Tooth disease type 2.