Charcot-Marie-Tooth Disease (CMT) affects the nerves outside the brain and spine, known as the peripheral nerves, and is passed down through families and across gene and inheritance pools. It is one of the most common disorders that is passed down genetically, in fact, and can cause problems in at least 40 different genes that manifest as 40 separate forms of the disease.
The disease leads to damage of the myelin sheath that covers nerve fibers, and this damage creates an opening for nerve fibers to be damaged. Nerves can be affected quite severely depending on the form of the disease undertaken, though for many the affects can be minimized and worked through with extensive physical therapy.
Family history is a very important risk factor in many cases of CMT, as people are affected by this through their inheritance and as a product of their specific genes, as well as any abnormal family genetic issues. Thus, scientists are studying family histories and gene mutations to more completely understand how to fight CMT as well as how it affects people’s nerves and their nervous systems in the brain.
Other than the inheritance and genetic causes, CMT does not have any known acute or viral causes, and is not affected by any outside forces or external causes like other viruses or disorders. Not much more is known about the causes of CMT than this gene mutation, and how the genes mutate in the first place is still up for debate to reach a consensus among the scientific community.
Symptoms show themselves primarily in nerves that stimulate movement, including those in the legs, which are affected first and most severely in most cases of CMT. These symptoms typically manifest themselves in mid-childhood, and or early adulthood, and may include foot deformities, very high arches in the feet, loss of lower leg muscle causing skinny calf muscles, numbness in the feet or legs, and more.
Additionally, symptoms may show a “slapping” gait, involving the feet hitting the floor hard while walking, and weakness of the hips, legs, or feet. Additional symptoms for many people are shown in the arms and hands, including the formation of claw-like hands and other physical deformities among patients.
There is no known cure for CMT, though things like orthopedic shoes may make it easier to walk and move around. Physical therapy may help maintain muscle strength, too, and improve daily functioning for those with the disease.