Gene therapy hope for Menkes Disease
Studies in GM mice have shown that a combination of gene therapy and copper injections could be effective in treating Menkes Disease, a lethal and progressive disease that mainly affects young boys.
Menkes Disease is caused by a defective copy of a gene called ATP7A. Babies with the defective gene are not able to process copper properly, leading to muscle weakness and poor development of the nervous system. Currently the only treatment is daily copper injections, which are not very effective. Affected infants usually die before they reach the age of 10.
Because the underlying cause of the disease is genetic, doctors hope that gene therapy may be used. In gene therapy, a harmless virus containing the normal gene is used to swap the faulty gene for a healthy one. Scientists used GM mice with a defective copy of ATP7A as a model of the disease in humans. Like humans, these mice usually die in infancy.
The mice were treated with a virus containing a normal ATP7A gene injected directly into the brain, and also given copper injections. Mice given just gene therapy or copper injections died within three weeks. Mice given both treatments lived at least three times longer and one in five lived to 10 months (adulthood for mice).
The researchers found that the gene had become incorporated into the mouse genome in key cells required for brain development. Copper levels in the brains of mice receiving both treatments were found to be higher than the mice receiving just one treatment and damage to the nervous tissue was also reduced.