These patients have peculiar phenotypic features, are generally younger than in classical CIDP, and have poor response to IVIg and antibodies—mainly of IgG4- and IgG3-subtype—to nodal-paranodal antigens namely neurofascin-155, contactin-1 and caspr1 in the paranodal region, and neurofascin-186/-140 in the nodal region [32–35]. This evidence concerns the gene CNTNAP1 and chronic inflammatory demyelinating polyradiculoneuropathy.