Charcot-Marie-Tooth (CMT) disease, also known as peroneal muscular atrophy (PMA) and hereditary motor sensory neuropathy (HMSN), is a neurological disorder named after the three physicians that discovered it in 1886 – Jean-Martin Charcot, Pierre Marie, and Howard Henry Tooth. Although CMT affects nearly 115,000 people, many people have never heard of it. CMT is not usually life-threatening and rarely causes damage to the brain. It does, however, cause damage to the peripheral nerves – tracts of nerve cell fibers that connect the brain and spinal cord to muscles and sensory organs. This nerve damage, or neuropathy
, causes muscle weakness and wasting, and some loss of sensation, in the extremities of the body: the feet, the lower legs, the hands and the forearms.
CMT is caused by defects in genes – which are recipes for making proteins that serve essential functions in the body. People with CMT develop muscle weakness, contractures and bone deformities, sensory loss and associated symptoms. There are many types of CMT categorized by the different age of onsets, inheritance pattern, severity, and whether they’re linked to defects in axon or myelin. For example, CMT3, better known as Dejerine-Sottas (DS) disease, is more common in infants, and it has an inheritance of autosomal dominant – inheritable through a faulty gene contributed by either parent – and autosomal recessive – inheritable through a faulty gene contributed by each parent. Children with DS acquire motor milestones slowly, and some never gain the ability to walk. Others begin walking at preschool age or later, but many require wheelchairs by their teen-age years.
Scientist are still investigating treatments for CMT. However, some scientists hope to treat CMT by finding ways to improve axon-Schwann cell interaction and axonal transport. Other scientists are investigating gene therapy for CMT. Still other scientists hope to treat CMT with stem cells – primitive cells capable of generating specific cell types in the body.