Multiple Sclerosis in Charcot-Marie-Tooth Disease Type 1A - A Case Report and Literature Review.

Central nervous system (CNS) demyelination is an uncommon observation in patients with Charcot-Marie-Tooth disease (CMT). Where it does occur, it is usually associated with X-linked CMT. We present a case of CMT type 1A with a likely de novo mutation who experienced initial symptoms, and subsequent exacerbation, of multiple sclerosis following respiratory infection. A review of the literature reveals that reports of CMT1A with CNS demyelination are rare. We propose that the mutations in the PMP22 gene result in an over-expression of PMP22 mRNA, which overcomes the normal suppression by miRNA species that occurs in the CNS. This abnormal expression of PMP22 protein may, in certain circumstances, exacerbate autoimmune responses to result eventually in CNS demyelination.