When neuropathic pain is present as a symptom of CMT, it is comparable to that seen in other peripheral neuropathies, as well as postherpetic neuralgia and complex regional pain syndrome, among other diseases. Causes
Charcot–Marie–Tooth disease is caused by genetic mutations that cause defects in neuronal proteins. Nerve signals are conducted by an axon with a myelin sheath wrapped around it. Most mutations in CMT affect the myelin sheath, but some affect the axon. Classification
CMT is a heterogeneous disease and the mutations linked to it may occur in a number of different genes. Based on the affected gene, CMT is categorized into several types and subtypes. Chromosome 17
The most common cause of CMT (70–80% of the cases) is the duplication of a large region on the short arm of chromosome 17 that includes the gene PMP22.Some mutations affect the gene MFN2, on chromosome 1, which codes for a mitochondrial protein. Mutated MFN2 causes the mitochondria to form large clusters, or clots, which are unable to travel down the axon towards the synapses. This prevents the synapses from functioning. X-linked CMT and Schwann cells
CMT can also be produced by X-linked mutations and is named X-linked CMT (CMTX). In CMTX, mutated connexons create nonfunctional gap junctions that interrupt molecular exchange and signal transport.The mutation can appear in GJB1 coding for connexin 32, a gap junction protein expressed in Schwann cells.
Here, the zona fasciculata and zona reticularis, in response to ACTH, secrete glucocorticoids, in particular cortisol. In various peripheral tissues, notably the kidneys, cortisol is inactivated to cortisone by the enzyme corticosteroid 11-beta-dehydrogenase isozyme 2. This is crucial because cortisol is a potent mineralocorticoid and would cause havoc with electrolyte levels (raising blood sodium and lowering blood potassium levels) and raise blood pressure if it were not inactivated in the kidneys.Because cortisone must be converted to cortisol before being active as a glucocorticoid, its activity is less than simply administering cortisol directly (80–90%). Popular culture
Addiction to cortisone was the subject of the 1956 motion picture Bigger Than Life, produced by and starring James Mason. Though it was a box-office flop upon its initial release, many modern critics hail the film as a masterpiece and brilliant indictment of contemporary attitudes toward mental illness and addiction. In 1963, Jean-Luc Godard named it one of the ten greatest American sound films ever made.John F. Kennedy was regularly administered corticosteroids such as cortisone as a treatment for Addisons disease. See also
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Central serous retinopathy
Corticosterol

Notes
Bibliography
Bonagura J., DVM;  et al. (2000). Current Veterinary Therapy. Vol. 13. pp. 321–381. Ingle DJ (October 1950). "The biologic properties of cortisone: a review". J. Clin. Endocrinol. Metab. 10 (10): 1312–54. doi:10.1210/jcem-10-10-1312. PMID 14794756. Woodward R. B.; Sondheimer F.; Taub D. (1951). "The Total Synthesis of Cortisone". Journal of the American Chemical Society. 73 (8): 4057. doi:10.1021/ja01152a551.