What is CMT?

Frequently Asked Questions ...

What is Charcot-Marie-Tooth (CMT)?: Charcot-Marie-Tooth disorder, or CMT, is a group of genetic disorders of the peripheral nervous system-that is, it affects the sensory and muscle control nerves of the lower arms and legs. For many years, it has been known that CMT is one of a few disorders which show all the known patterns of inheritance (dominant, recessive and x-linked inheritance). This is because there are a number of different varieties.

What are the medical names for CMT?: CMT is also know as Peroneal Muscular Atrophy and Hereditary Motor Sensory Neuropathy types 1 and II and X. The peroneal type of muscular atrophy was separated from other forms of progressive neuromuscular disorders in 1886 simultaneously by the doctors, Charcot and Marie in France and Tooth in the UK.

How common is CMT?: CMT is the most commonly inherited disorder of the peripheral nervous system. As many as 1 in 3000 people in Australia could have CMT and it is believed that 50% of CMT persons are unaware that they have it.

Who can get CMT?: CMT in most cases is a familial disorder - although there are sporadic cases which have no family history of the disease.

What are the symptoms of CMT?: Sufferers of CMT have lifelong weakness in the distal muscles-that is to say those at the end of the arms and legs (peroneal muscular atrophy), usually manifesting in childhood and adolescence and frequently leading to foot and hand deformity. The most common foot deformity is a very high arch (pes cavus) with clawing of the toes. There can also be other problems such as weakness in the ankles, foot drop and wasting of leg muscles. In the upper limbs there is weakness of the grip and of wrist movements which can cause difficulty in fine finger movements and hand tremors. The condition can result in clumsiness and poor balance. In very rare cases scoliosis (curvature of the spine) may occur. CMT is not life threatening and the symptoms can be alleviated by physiotherapy, Orthotics and if complications develop, surgery may be necessary.
In children early treatment can assist normal foot development. There is no cure for CMT at present.

What drugs should be avoided?: There are few proven drugs that a CMT person should avoid. Vincrisine, a cancer therapy is one. For a detailed list of drugs that should be considered contact the Association.

What research is being carried out?: Research is being undertaken world-wide.