GENE FOUND FOR CMT2A

A second gene that, when flawed, leads to the type 2A form of CMT, has been identified by a multinational research group that studied seven families from varying ethnic backgrounds with this form of the disease, publishing results online in Nature Genetics.

In type 2 forms of CMT, the primary problem is thought to be in the nerve fiber itself, rather than in its myelin sheath, the site of the problem in the type 1 forms.

The new gene, on chromosome 1, is for a protein called mitofusin 2 (MFN2), which plays a role in the behavior of mitochondria, the energy-producing units of cells and crucial contributors to the health of the nervous system.

Previous research identified the gene for the protein known as kinesin 1B (KIF1B) as a culprit gene for CMT2A in one Japanese family, but so far the MFN2 gene appears to be the more common cause of the disorder.

“We conclude that mutations in MFN2 are the primary cause underlying CMT2A,” the investigators say in their paper. “The present study demonstrates a new mechanism for axonal [nerve fiber] neuropathies [nerve diseases] and should provide insight into the pathophysiology of neuropathic disease, both hereditary and acquired.”