Keywords

Charcot-Marie-Tooth, CMT, CMT1A, demyelinating CMT, foot drop, genetic diagnosis, genetic testing, inherited neuropathies, muscle atrophy, neuromuscular disease, pediatric neurology, rehabilitation, peripheral neuropathy, PMP22

 

Authors

  1. Inman, Emma

Abstract

ABSTRACT: Charcot-Marie-Tooth (CMT) is a hereditary condition that affects the myelin sheath of peripheral nerves causing muscle weakness, atrophy, and peripheral neuropathy. This is a firsthand reflection of living with CMT disease from my personal experience and through my family. I hope this provides informative education to practitioners or individuals who may not be familiar with CMT.

 

Article Content

I was about 10 years old when I decided to take a break from playing outside with the neighborhood kids to come along on a short road trip to Wichita, Kansas, with my mom to a doctor's appointment. I knew from early childhood that my mom had health issues and problems with her feet. However, as a young child, I did not take much interest in her health.

 

On this trip, I was wearing flip-flop sandals and pacing around the doctor's office while my mom was being fitted for her orthotics. The provider who was fitting her shoes and calves said to me, "You know you have CMT [Charcot-Marie-Tooth] too, right?" I did not think much of it at the time, and although I have never been formally diagnosed, I never would have guessed that, 20 years later, those words would still be engraved in my head.

 

Charcot-Marie-Tooth is neuromuscular disease that affects the myelin sheath and peripheral nerves causing muscle atrophy and weakness. It is hereditary, affects 1 in 2500 people worldwide, and is more common than multiple sclerosis.1 The severity of CMT can vary greatly among patients, even within the same family. The CMT Association identifies CMT as the most commonly inherited form of peripheral neuropathy.1 There are actually many different variations of severity in disease response, even among individuals in the same family. Nurses should be aware that CMT causes motor change and every person with CMT has differing needs. However, CMT is not and will never be a death sentence.

 

Fast forward to high school, that is when my CMT really set in. That is when I knew that I had something different. We all know that high school is known for being some of the best years, or some of the roughest years; for me, it was rough. My CMT is most easily seen in the way I walk. I have extremely high arches, hammertoes, and narrow heels. Kids were mean and called me "penguin" for the way that I walked. I have "foot drop," and I kick my legs out when I walk. This made it difficult to find shoes, other than athletic shoes, that fit me just right. The name-calling and making fun ended promptly after high school, as most adults are more polite and seem less affected by physical differences.

 

I now have 2 small children-daughter Charlie is the youngest. Charlie was around 6 months old when we noticed something was not quite right, especially compared with her brother who is 2 years older. It clicked pretty instantly with me that she had CMT. Instead of hands and knees crawling, Charlie would slither around with her stomach on the ground. She would pull herself forward with the left side of her body and drag her right side, almost as if she had a stroke (Supplemental Video Content 1, available at http://links.lww.com/JNN/A203). This continued for several months and concerned our pediatrician to the point that he insisted on genetic testing.

 

Genetic testing is a hard parental decision. We held off and continued to watch Charlie grow. She turned 1 year old in November of that year and was not walking yet. Around January, at the age of 14 months, Charlie started walking; however, instead of using her core strength in her stomach to hold herself upright, she would swing one side of her body, pause, and then swing the other side. Our pediatrician saw the way she was walking and pushed even harder for genetic testing at this time. This time, we agreed. He swabbed Charlie's cheek, sent it off for testing, and called me personally 3 days later. He sounded sad, and he was apologetic for the results he was about to give (Figure 1). "I am so sorry, but Charlie has Charcot-Marie-Tooth Type 1A." I assured him that it is okay. Charlie is perfect just the way she is, and that CMT is not a death sentence.

  
Figure 1 - Click to enlarge in new windowFIGURE 1. Chromosomal Microarray

A highly condensed review of the literature might be helpful. CMT type 1A scientifically is a duplication of PMP22, which is a gene housed inside chromosome 17 on the DNA structure of an individual.2 CMT1A is the most common type of CMT, accounting for two-thirds of the affected population. Seven types of CMT are broken down into 35 subtypes, with the most common being CMT1A, which is often referred to as the demyelinating CMT.3,4 This is because the duplication of the PMP22 gene causes disruption in the formation and function of the myelin covering peripheral nerves.4 The National Center resources5 indicate that "usually, people with CMT1A are slow runners in childhood, can develop high arches and hammertoes and often require the use of braces for ankle support." Often, these individuals have issues with their feet and legs before upper extremities. The arms and hand difficulties in individuals with type 1A usually come approximately 10 years after the start of legs and feet.2

 

Charlie sees a geneticist, a physical therapist, occupational therapist, rehabilitation physician, and nutritionist every year at the children's hospital in Kansas City to ensure that she is progressing along with her peers at a normal rate. Last year, Charlie leapfrog jumped down the rehabilitation hallway-an astonishing accomplishment that surprised even her physiatrist. The care team was astonished that she had such great quadricep strength to be able to do that.

 

Charlie has had many more falls than her big brother. Furthermore, in the early stages of walking and running, she becomes fatigued much more easily and much quicker. She gets leg cramps behind her knees every couple of weeks, but these are easily resolved with medicines. Charlie, like every child with CMT, is unique. As a neuroscience nurse, I am impressed with the care she has received and I am happy to share what I have learned in my CMT journey.

 

References

 

1. Charcot-Marie-Tooth Association. CMT fact sheet. Available at https://www.cmtausa.org/branch-leader/branch-leader-toolbox/cmt-facts. Accessed September 14, 2019. [Context Link]

 

2. Jani-Acsadi A, Ounpuu S, Pierz K, Acsadi G. Pediatric Charcot-Marie-Tooth disease. Pediatr Clin North Am. 2015;62(3):767-786. [Context Link]

 

3. Pareyson D, Saveri P, Pisciotta C. New developments in Charcot-Marie-Tooth neuropathy and related diseases. Curr Opin Neurol. 2017;30(5):471-480. [Context Link]

 

4. Muscular Dystrophy Association. Charcot-Marie-Tooth disease. Available at https://www.mda.org/disease/charcot-marie-tooth. Accessed September 14, 2019. [Context Link]

 

5. US Deptartment of Health and Human Services. Genetic and rare diseases information center. Available at https://rarediseases.info.nih.gov/diseases/1245/charcot-marie-tooth-disease-type. Accessed September 14, 2019. [Context Link]