How much do you know about CMT? Take the quiz to find out and let us know how you did! Answers at the end. Good luck! For more information on CMT, CMTA or CMTA STAR research, please visit: http://www.cmtausa.org
*Denotes explanation at the bottom of page.
1) CMT is a genetically heterogeneous disorder. What does heterogeneous mean?
a. Like the process of breaking down fat molecules in milk, CMT can be broken down into smaller particles through a high-pressure procedure.
b. Mutations in different genes can produce the same clinical symptoms.
c. A term used to explain the genius-level IQ of most people with CMT.
d. Belonging to the same family,
2) When researchers study the natural history of CMT, what exactly are they doing?
a. They are trying to figure out which components of CMT are artificial.
b. It’s all old news.
c. They are studying the progression of CMT over time.
d. They are trying to determine the origins of CMT and when it all began.
3) People with CMT often use AFOs. What does AFO stand for?
a. Ankle Foot Orthosis
c. Air Force One
d. Area Financing Officer
*4) What is HNPP?
a. HNPP stands for Hereditary Neuropathy with Liability to Pressure Palsies
b. HNPP is a sub-type of CMT.
c. HNPP is most often caused by a deletion of the PMP22 gene.
d. All of the above.
5) What is Foot Drop?
a. An abrupt 1-foot fall or slope
b. Inability to lift the foot at the ankle due to weakness or paralysis of the anterior (front) muscles of the lower leg.
c. A secret play in football when the quarterback drops the ball 1 foot from the goal line.
d. The name of a used shoe company.
6) To date, how many genes have been found to cause CMT?
b. Over 100
d. We cannot count that high.
7) If a child inherits CMT from a parent, will it be the same type of CMT?
a. Yes. The type of CMT does not change between generations.
b. No. CMT is variable and changes sub-types from one generation to the next.
c. Children do not inherit CMT from parents.
d. I do not know, but the child will love Country Music Television!
*8) Is CMT like Muscular Dystrophy (MD) or Multiple Sclerosis (MS)?
a. Yes, because CMT is under the Muscular Dystrophy umbrella.
b. No. They are completely different and separate diseases.
c. No one really knows.
d. Yes, because MD, MS and CMT are just different acronyms for the same disease.
9) Anyone in the world can be born with CMT because everyone is susceptible to random or de novo gene mutations.
a. Only people in the US are susceptible to new, random mutations.
b. This statement is false.
c. I have no idea if this is true or false.
*10) If two people who have an autosomal dominant (“Autosomal” means that the gene in question is located on one of the numbered, or non-sex, chromosomes. “Dominant” means that a single copy of the disease-associated mutation is enough to cause the disease) form of CMT (like CMT 1A) have children, what is the chance that their children will inherit CMT?
*11) What is Dominant Intermediate Charcot-Marie-Tooth Disease (DI-CMT)
a. A rare, dominantly inherited type of CMT
b. Just an expression used to liken the inheritance of CMT to a roll of the dice.
c. Does not exist. Just a made up name to throw you off the right answer.
d. A type of CMT that affects people with Type A personalities.
12) Your CMT genetic test comes back negative. What does this mean?
a. No one really knows.
b. You still may have CMT. There isn’t any one lab testing for all known mutations in any one test. Moreover, not all genetic mutations underlying CMT have been found or can be detected with a DNA test.
c. A negative result rules out CMT since all sub-types of CMT are easily recognizable.
d. Retake the test 5-6 more times to be sure of the results.
13) What does the CMTA’s research initiative, STAR, stand for?
a. Strategy to Accelerate Research
b. Strategy to Advance Rats
c. Situation, Task, Action Result
d. Sewage Telecommunication Access By Robot
14) Although there is no medicinal cure for CMT, we can treat the symptoms of CMT with:
a. Exercise, physical and occupational therapy, healthy diet
b. Braces and other orthopedic devices
c. Surgery can help prevent or reverse foot and joint deformities
d. All the above
15) Since the launch of STAR in 2008, how much money has the CMTA spent on treatment-driven CMT research?
a. 1 million
b. 5 Million
c. 10 Million
d. 16 Million
- For a great article on HNPP by CMT expert JunLi, MD, please see: https://bestfoot4wardblog.com/2020/02/20/hnpp-the-latest/
- The ankle dorsiflexors, the muscles that lift up the foot and ankle, are frequently involved in foot drop. When the Tibialis Anterior muscle weakens, the foot begins to drop down. This is usually a gradual process, occurring over months or years.
- Charcot-Marie-Tooth (CMT), Multiple Sclerosis (MS) and Muscular Dystrophy (MD) are three completely separate and distinct diseases. Remember that our neuromuscular system really starts at the brain, which is the master computer, and sends signals to the motor (muscles) via the spinal cord (an intermediate connecting cable), which hooks up to the peripheral nerves (the connecting lines between brain and muscle).
- Muscular Dystrophy is a disease of the muscle itself, which causes weakness of varying degrees. There are many forms of MD. Sometimes the heart is involved because it is a muscle too. The lungs can also be affected because the breathing muscles are weak (similar to CMT, although in CMT it is because the phrenic nerves are affected, which in turn weakens the diaphragm, the main breathing muscle).
- CMT is primarily a disease of the peripheral nerves (the connecting lines between brain and muscle). CMT causes weakness and impaired sensory perception because the signal can’t get to and from the brain to muscle and skin, among other things. The muscles shrink because they aren’t getting the proper signals, but the muscles themselves are not directly diseased per se.
- Multiple Sclerosis is a disease of the brain and spinal cord. It can affect both movement and sensory perception and sometimes thinking processes.
- There is a 75% chance that they will have a child that is affected. Broken down, there is a 50% chance that the child will get the duplication from one or the other parent, a 25% chance they will get it from both parents (i.e. for CMT1A they will then have 4 copies of the PMP22 gene), and a 25% chance they will not inherit CMT and have the normal copy number of PMP22. We have seen a few cases of kids that have inherited 4 copies of the PMP22 gene and they seem to be more significantly affected than their parents, but we have not looked at this longitudinally because it is rare. (Answered by Shawna Feely, CGC)
- CMT-DI takes its name from the nerve conduction velocity (NCV), which is considered intermediate. The nerve biopsies from patients with DI-CMT have shown both axonal degeneration as well as demyelination. Dominant mutations in the genes DNM2, MPZ, and YARS are associated with DI-CMT types B, D, and C, respectively.