We compared mitochondrial phenotypes in cells from four CMT2A patients, two having MFN2 mutations within the canonical dynamin/Fzo-like GTPase domain (MFN2 T105M in the G1 motif and MFN2 R274W between the G4 and G5 motifs), and two with mutations in the MFN2 coiled-coiled helix bundle core (MFN2 H361Y and R364W). The gene discussed is DNM1; the disease is Charcot-Marie-Tooth disease type 2A1.