By Kenneth Raymond

As a patient and an advocate and a student of the condition, I am often asked, “What exactly is CMT?”. My response is usually along the lines of:

“CMT stands for Charcot-Marie-Tooth disease, a rare inheritable neuromuscular peripheral neuropathy named after the three doctors (Jean-Martin Charcot, Pierre Marie and Howard Henry Tooth) who first described it more than 130 years ago. CMT causes the peripheral nerves to stop working correctly; and this leads to muscle weakness and atrophy, joint changes, difficulty with walking, and hand issues. Some who have CMT have breathing issues, hearing impairment, vision problems, bladder issues, and GI issues. The disease progressively worsens as you age and there is currently no treatment or cure.

Although a rare disease by every statistical and modeling measure – affecting 1 in every 2,500 people in the U.S. and about 3 million people worldwide – CMT is the most commonly inherited peripheral nervous system disease. ”

But honestly, there isn’t a one-size-fits-all answer simply because CMT can and does affect everybody differently, even within the same family. The mix of symptoms, gravity of individual symptoms, rate of disease progression, and overall disease severity can be quite different for every CMTer. There are CMTers in wheelchairs, using canes, who need walkers, etc. Some CMTers wear leg braces. Some CMTers have breathing issues. Some CMTers have severely twisted and deformed feet. Some CMTers have hearing loss. Some CMTers have speech impairment. Moreover, I’m confident there are many hidden symptoms that go unmentioned and unnoticed. What one CMTer experiences cannot be used to gauge or predict what the disease will be for the next CMTer, regardless of subtype.

Doctors might describe CMT as an inheritable, multisystem neuromuscular peripheral polyneuropathy. Inheritable because each of the genetic mutations that cause CMT are inheritable. Peripheral because CMT is a disease of the peripheral nerves. Polyneuropathy because CMT affects more than one peripheral nerve at a time (poly), as opposed to only one peripheral nerve (mononeuropathy). Neuropathy because peripheral nerve disease. Then, multisystem because CMT can affect hearing, vision, breathing, genitourinary, and much more, in addition to feet/legs/hands.

There are also plenty of wrong answers, such as the suggestion that CMT is an autoimmune disease. While CMT might share symptoms with some autoimmune diseases, such as Multiple Sclerosis (MS) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) for example, CMT is decidedly not an autoimmune disease.

CMT, for me personally, is twisted, contorted, crooked feet that have led to tendons tearing, requiring corrective reconstruction surgery of my right foot (and upcoming surgery for my left foot). CMT, for me, is weakened hands that easily cramp, a knee that used to dislocate before corrective surgery, bilateral hearing loss, unrelenting fatigue, chronic whole-body pain, progressively weakening upper leg muscles, spine changes (kyphoscoliosis), premature degenerative joint changes, speech/vocal difficulties, and for me, CMT is breathing issues. For another CMTer, CMT is wheelchair dependency, an inability to hold and use a pen or pencil, 24/7 mechanical ventilation via tracheostomy, and total deafness. Yet, for another, CMT is none of these things, or is a combination of these.

If you were to line up ten random patients—who have CMT or whose loved ones have CMT, and ask each, “What is CMT?” each of the ten answers are likely going to be very different. The differences are not born of inaccuracy or of a misunderstanding of their disease. The variances instead come from how each person individually experiences CMT.

What is CMT? For me, CMT is a cruel and often debilitating neuromuscular disease that looks very different from person-to-person. For me, what was once an easy answer to a complex question, or what was a complex answer to an easy question, has become exponentially more difficult to answer. As a CMTer, it’s easy to answer the question by simply describing what CMT looks like for me. As an advocate, however, I’ve learned my “elevator speech,” falls short of accurately describing the complexity of the disease and how it can affect each of us differently.

About the author: Kenneth Raymond was first diagnosed clinically with CMT1 in late 2002, at the age of 29. He was genetically confirmed to have CMT1A a year later. Kenneth has since devoted his life to studying, researching, and learning all things CMT, with an emphasis on the genetics of CMT as they relate to everyday CMTers. As a member of the Charcot-Marie-Tooth Association’s Advisory Board, Kenneth serves as a CMT genetics expert, a CMT-related respiratory impairment expert, and as a CMT advocate who is committed to raising CMT awareness through fact-based information rooted in the latest understandings of CMT.

This piece is adapted from a longer blog he posted to his website: https://www.expertsincmt.com/experts