18-Hereditary sensory-motor neuropathy CMT 1C caused by a novel mutation in LITAF gene overlapped with an immune mediated asymmetric chronic inflammatory neuropathy (MADSAM)

Abstract

We report a family with a novel missense mutation in a LITAF gene (c348G > C p.Trp116Cys). One of the family members had a rapid stepwise deterioration of symptoms (subacute onset demyelinating asymmetric neuropathy of upper limbs ) in his 52 years. In patients with such kind of a rare mutation subacute or step progression can appear. Electrophysiological investigation can show temporal dispersion and conduction blocks – which is not typical feature in hereditary neuropathies, but was described in some rare mutations and also immune mediated neuropathies. Investigation of CSF, nerve conduction studies, MRI of brachial plexi were not significant for immune mediated neuropathy. We used calculated electrophysiological parameters - modified F ratio (MFR) and terminal latency index (TLI). These parameters were normal in mother and son who had the same mutation in LITAF gene, objectively confirmed moderate symmetric demyelinating polyneuropathy with conduction blocs, but they were without subjective difficulties. They were changed in our patient – before treatment (TLI was a little bit reduced 0.248 and MFR was prolonged 3.21) After 6 months of treatment with IVIG - paresthesias disappeared, weakness of upper limbs was reduced, minimal F wave latency was getting shorter, TLI (0, 3) and MFR (1, 8) returned to normal values.