Contactin-associated protein-like 2 autoimmunity is an uncommon disorder resulting in peripheral nerve hyperexcitability or encephalitis. In a fifth of cases, onset may be provoked by thymoma, but other associations are largely unknown. We report a patient with anti-contactin-associated protein-like 2-related peripheral nerve hyperexcitability arising in the setting of Charcot-Marie-Tooth type 4F and discuss potential mechanisms underlying the association.

Charcot-Marie-Tooth disease (CMT) constitutes a group of heterogeneous hereditary motor and sensor neuropathies. Mutations in the periaxin (PRX) gene cause CMT4F with an autosomal recessive early-onset demyelinating neuropathy and are extremely rare in a non-Romani white population.
We report on a 66-year-old Italian man presenting with slowly progressive and late-onset demyelinating CMT. The molecular analysis was performed using a custom panel containing 39 genes associated with the CMT phenotype.
The patient harbored a homozygous PRX 71-nucleotide deletion (c.3286_3356del71, I1096fsX17).
This is the first report that describes such a genetic mutation in a population of non-Romani origin.