Occurrence of optic neuritis and cervical cord Schwannoma with Charcot-Marie-tooth type 4B1 disease

Charcot-Marie-Tooth neuropathy type 4B1 (CMT4B1) disease is a rare subtype of CMT4 with reported association of facial weakness, vocal cord paresis, chest deformities, and claw hands. We report the unusual occurrence of optic neuritis and cervical cord schwannoma in a male individual with confirmed CMT4B1 disease. Sequencing of the MTMR2 gene revealed a novel nonsense homozygous mutation c.1768C>T (p.Gln590*). The mutation was identified in affected relatives of the proband and a second, apparently unrelated, family. The rare association of optic neuritis or schwannoma with genetically confirmed CMT1A has been individually observed, but never with recessive CMT. To the best of our knowledge, the occurrence of optic neuritis and cervical cord schwannoma in the same patient has never been reported with any form of CMT including CMT4B1. In similar cases, we recommend immediate medical attention to rule out the possibility of schwannomas in patients with all demyelinating CMT subtypes in case of the development of focal neurological signs or acute worsening of clinical status.