Charcot‐Marie‐Tooth disease type 1 and 2‐an immunohistochemical study of muscle fibre cytoskeletal proteins and a maker for muscle fibre cytoskeletal proteins and a marker for muscle fibre regeneration

In 10 patients with Charcot‐Marie‐Tooth disease type 1 (CMT1), hereditary motor and sensory neuropathy (HMSN) type, 1, deymyelinating form, and 10 patients with CMT2, HMSN type 2, axonal form, monoclonal antibodies directed against dystrophin, spectrin, desmin, vimentin and a myoblast and satellite‐cell related antigen, Leu‐19, were applied to muscle biopsies from the anterior tibial muscle. Data from the biopsies were compared with those from 20 age‐and sexmatched healthy controls, Both CMT1 and CMT2 patients had normal stainings for dyustrophin and spectrin, indicating a normal muscle fibre cytoskeletal structure. In the CMT2 group, seven patients had increased staining for desmin in the majority of the atrophic fibres. In the CMT1 group, six of the patients had a normal desmin stating in normal sized and in atrophic muscle fibres, while the remaining four patients had an increased staining for a desmin in a few atrophic muscle fibres. Seven CMT2 patients and one CMT1 patient had increased staining of vimentin in some atrophic muscle atrophi muscle fibres. These immunohistochemical data support earlier findings of muscle fibre histopathological differences in CMT1 and CMT2 patients, possible reflecting different pathophysiological mechanisms in the two disorders.