What is CMT


Charcot-Marie-Tooth disease  is named after the three doctors who first described it in 1886, Professor Jean-Martin Charcot (pronounced sharko)(1825-1893), his student, Pierre Marie (1853-1940), who both worked in Paris at the Hospital de Salpetriere named after the former gunpowder factory site where it still stands, and Dr. Howard Tooth (1926-1956) of London.

It is also called peroneal muscular atrophy (PMA) because the peroneal muscle down the front of the shin that enables you to pull your foot up is usually the first muscle to be affected. A weakened peroneal muscle can cause sloppy walking, drop foot which causes tripping and you must lift your leg from the thigh so that your toes clear the ground and your foot slaps onto the ground, hopefully heel first.

CMT also has a third and more recent name, hereditary motor and sensory neuropathy (HMSN). This name more accurately describes the syndrome because it is hereditary, can affect both or either the ability to move (motor) or the ability to feel (sensory). I have seen many people who cannot feel their feet or legs in a stocking pattern and many who cannot move their ankles, feet and toes and some who cannot feel or move anything from the knees down. Most people experience some loss of movement.

CMT is primarily a disease of the nerves whereby the myelin or insulating sheath of myelin on the nerves does not stay intact and the messages from the brain to the muscles through the nerves are not carried properly.

It differs from muscular dystrophy in that people who have CMT are born with normal muscles. The muscles atrophy because the CMT affected nerves that serve them cannot properly send the message from the brain for them to move. Therefore, muscles can atrophy even though they are being used.

People with muscular dystrophy have a problem with their muscles from the beginning. CMT is a muscular atrophy not a muscular dystrophy.

CMT is not well known but it is not rare. Many people do not know they have it even though it is carried in families sometimes for generations. Often people write to me and tell me their family just thought they'd all inherited Grandma Jones' bad feet. One family member being properly diagnosed usually turns on the light bulbs for everyone else in that family.

CMT can be inherited three ways but most cases are inherited autosomal dominate pattern meaning it comes directly down a line from parent to child. In this form of inheritance there is a 50/50 chance at each conception that the child will have CMT. We have a publication that explains the ways CMT can be inherited and the genetic research that is going on as well as testing currently available.