OBJECTIVE:

Mutations of the mitofusin 2 gene (MFN2) may account for at least a third of the cases of Charcot-Marie-Tooth disease type 2 (CMT2). This study investigates mitochondrial cellular bioenergetics in MFN2-related CMT2A.

METHODS:

Mitochondrial network morphology and metabolism were studied in cultures of skin fibroblasts obtained from four CMT2A patients harboring novel missense mutations of the MFN2 gene.

RESULTS:

Although the mitochondrial network appeared morphologically unaltered, there was a significant defect of mitochondrial coupling associated with a reduction of the mitochondrial membrane potential.

INTERPRETATION:

Our results suggest that the sharply reduced efficacy of oxidative phosphorylation in MFN2-related CMT2A may contribute to the pathophysiology of the axonal neuropathy.