An autosomal recessive axonal form (OMIM:605589) of Charcot-Marie-Tooth disease* characterised by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal arm muscles.
*Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, is divided into 2 main groups based on electrophysiologic properties and histopathology: primary peripheral demyelinating neuropathies (designated CMT1) and primary peripheral axonal neuropathies (CMT2). Neuropathies of the CMT2 group are characterised by signs of axonal regeneration in the absence of obvious myelin alterations, normal or slightly reduced nerve conduction velocities, and progressive distal muscle weakness and atrophy. Nerve conduction velocities are normal or slightly reduced.
Molecular pathology Defects of MED25, which encodes a subunit of the mediator complex–MC, a transcriptional coactivator complex thought to be required for gene expression, cause Charcot-Marie-Tooth disease—axonal—2B2.
Synonym Charcot-Marie-Tooth neuropathy—2B2