Charcot-Marie-Tooth disease type 1A (CMT1A) is a dominantly inherited, slowly progressive, often-disabling symmetrical distal sensorimotor polyneuropathy, caused by duplication of 1.5 Mb on the short arm of chromosome 17 with consequent trisomy for PMP22 (peripheral myelin protein 22) encoding a peripheral nervous system myelin protein, that affects about 1 in 2000 people. Other than braces and other orthopedic interventions, no effective treatments of CMT1A are available. A report in 2004 by Passage et al1 found that treating PMP22 transgenic mice with a dose of ascorbic acid (AA; vitamin C) that would be equivalent to administration of 4 g of AA per day to an average adult human diminished peripheral nerve PMP22 mRNA abundance 10-fold. The findings that it also restored the peripheral nerve myelin sheath thickness to normal, improved clinical neurological function, and enhanced life span were greeted with great excitement among neuromuscular physicians.
Patel PI, Pleasure D. Whither Hope for Pharmacological Treatment of Charcot-Marie-Tooth Disease Type
1A?. JAMA Neurol. 2013;70(8):969-971. doi:10.1001/jamaneurol.2013.3285