Charcot Marie Tooth (CMT) disease is a hereditary sensory and motor neuropathy that affects the peripheral nerves. The symptoms are mainly seen during adolescence or early childhood but the disease is usually a genetic disease and would have been present for a long time. The severity varies from one individual to another but most people live a near-normal life. The symptoms mainly involve the nerves of the legs and hands and patients can have muscle weakness and loss of sensation. Respiratory muscle weakness can occur in some patients which can be life-threatening other than that most patients live with minimum disabilities.
What Leads To Charcot Marie Tooth?
The inheritance can be autosomal dominant, autosomal recessive or X-linked. Charcot Marie Tooth occurs due to mutations in different genes that give instructions to make proteins that are involved with the function of the peripheral nerves in the feet, leg, hands, and arms. The exact abnormality Charcot Marie Tooth gene mutation cause in these proteins is clearly not known. More than 30 gene mutations have been identified as causes for Charcot Marie Tooth. The most probable theory is a fault in these proteins impair the nerve conduction through axons or affect the cells that produce myelin in the nerve cells. The axons are the body of each nerve cell and it helps in the signal transmission between nerve cells. The nerves that are longer and nerves that transmit signals to appendages are affected more as the axons are longer in these nerves and with the mutation the signal transmission in these nerves becomes abnormal. Therefore, nerves in the extremities are affected more than other parts of the body. So, with time the peripheral nerves lose the ability to transport signals from the brain for muscle movement and lose the ability to carry sensory signals from peripheries to the brain. Different gene mutations in the same gene can cause several symptoms and different types of Charcot Marie Tooth.
70-80% of patients with CMT1 have mutations in the PMP22 gene. 10-12% of patients have CMT1 mutation in the MPZ gene. Some of the other types of CMT patients also have a gene mutation in the MPZ gene. 20% of CMT2 patients have a gene mutation in the MFN2 gene. 90% of CMTX patients have a gene mutation in the GJB1 gene. There is a huge list of gene mutations in different types of Charcot Marie Tooth. (1) (2) (3)
Can Charcot Marie Tooth Disease Be Cured?
There is no cure available for Charcot Marie Tooth. Treatment is mainly supportive and symptomatic management. Most patients have a normal life and improve the quality of life with symptomatic and supportive management. A multidisciplinary team should be involved with the management and this team should consist of a genetic counselor, physical therapist, occupational therapist, nurses, and orthopedic surgeon. Treatment is mainly symptomatic and mainly involves physical therapy and occupational therapy as the main symptoms are a weakness in extremities. This can improve the weakness and prevent muscle contractures. The sensation cannot be regained but the importance is patient being aware of the sensory loss and doing daily checkups for skin burns and other injuries as untreated injuries can lead to ulcers. Some patients develop breathing difficulties and these patients need devices that deliver air under pressure to the lungs especially at night. a pressure support ventilator that can be used to improve the symptoms.
Conclusion
The inheritance can be autosomal dominant, autosomal recessive or X-linked. Charcot Marie Tooth occurs due to mutations in different genes that give instructions to make proteins that are involved with the function of the peripheral nerves in the feet, leg, hands, and arms. More than 30 gene mutations have been identified as causes for Charcot Marie Tooth. The most probable theory is a fault in these proteins impair the nerve conduction through axons or affect the cells that produce myelin in the nerve cells. There is no cure available for Charcot Marie Tooth. Treatment is mainly supportive and symptomatic management. Most patients have a normal life and improve the quality of life with symptomatic and supportive management.
Also Read:
- Charcot Marie Tooth Disease or CMT: Symptoms, Causes, Types, Treatment
- Is Charcot Marie Tooth Disease Painful & Can CMT Skip A Generation?
- What Are The Ways To Prevent Charcot Marie Tooth Disease & Does It Reoccur?
- How Common Is Charcot Marie Tooth Or Is It A Rare Disease?
- Is Charcot Marie Tooth Disease A Disability?
- Is There A Surgery For Charcot Marie Tooth Disease?
- Coping Methods For Charcot Marie Tooth Disease
