NEFL and Charcot-Marie-Tooth disease type 1A: CMT1A is the prototype of the demyelinating form of CMT, so we performed a pilot Olink Neurology panel analysis of samples obtained from two other types of demyelinating CMT: CMT1B caused by mutations in the Myelin Protein Zero gene,30 and CMT1X, caused by mutations in the Gap Junction beta1 gene.31 For comparison, we also included samples from two other axonal forms of CMT: CMT2A, caused by mutations in the Mitofusin 2 gene32 and CMT2E caused by mutations in the NEFL gene.33 The level of TMPRSS5 was determined for a subset of CMT1A and samples of the other CMT subtypes and controls (Fig. 5).