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.