Charcot-Marie-Tooth is one of the most common hereditary neurological disorder that affects one in every 2,500 people. The condition, which takes its name from the three doctors who described the disease affects the peripheral nerves and causes sensory and motor deficiencies. The severity of symptoms is highly variable and its progression is gradual. The disease comes in two variants: the demyelinating form, which causes a decrease in the rate of transmission of signals in nerves, and the axonal form. Until recently, this last clinical form had no clear diagnosis.

Mutations in MFN2 gene

The study coordinated by IDIBELL researchers found that, in Spain, the most common cause of the axonal variant of the disease are mutations in the gene MFN2. This gene is responsible for the production of a protein called mitofusin 2, which allows the fusion of mitochondria, the cell elements responsible for energy production. Studies made in other countries have detected a highly variable incidence of MFN2 mutation among people affected by the axonal variant of the disease.

Researchers studied 85 families suspected of having the axonal variant of Charcot-Marie-Tooth disease, treated at Bellvitge University Hospital between 1994 and 2007. The authors have identified nine different mutations of the gene MFN2 in twenty-four patients from 14 affected families. Four of these mutations have not been described previously.

The coordinator of the study, head of IDIBELL’s Laboratory for Molecular and Genetic Diagnosis IDIBELL, Victor Volpini, highlights “the collaboration between basic and clinical research teams in the study” which, says, “will be an improvement in the diagnosis of patients and, therefore, in genetic counselling.”

This is the first population study conducted in Spain on the incidence of mutations in MFN2 gene among patients affected by the axonal variant of Charcot-Marie-Tooth.

Besides IDIBELL researchers, the study also involved researchers from the University Hospital of Angers (France).

Paper refference

Casasnovas C*, Banchs I*, Cassereau J, Gueguen N, Chevrollier A, Martínez-Matos JA*, Bonneau D, Volpini V*. J Med Genet. 2010 Apr;47(4):249-56.

*Investigadors IDIBELL