Neuralgic amyotrophy caused by gene defect

Neuralgic amyotrophy (HNA), a rare hereditary disease, is characterized by repeated attacks of pain in a shoulder, arm, and/or hand, followed by total or partial paralysis of the affected area. The pain and the loss of movement usually disappear within a couple of weeks, but sometimes recovery can take months or even several years.

Researchers from the Flanders Interuniversity Institute for Biotechnology studied several large families and identified the gene responsible for the disorder. They have now shown that HNA is linked to the long arm of chromosome 17, and that patients often display mutations or alterations in the genetic code of the Septin 9 protein. HNA is the first mono-genetic disorder caused by a defect in a gene of the Septin family.

The researchers do not yet know exactly how the Septin 9 protein functions in the peripheral nervous system or why mutations give rise to HNA. They do know that other members of the Septin family are involved in the cell division that forms the cytoskeleton and in the development of tumors.

The fact that mutations in Septin 9 prevent cell division from occurring properly can perhaps explain why so many HNA patients also have facial abnormalities.

Presently there are no effective therapies to slow or prevent the progress of neuralgic amyotrophy. The current treatment is merely supportive. The findings of this researcher create the first essential step in the development of a specific treatment. Now they know which gene is involved, scientists can acquire more insight into the molecular processes of this disease, which may ultimately lead to a therapy.