Demyelinating neuropathies

Purpose of review: To review recent advances in heritable demyelinating neuropathies and their genotype-phenotype correlations. Recent findings: Two themes dominated the literature on demyelinating neuropathies in the past 2 years: (1) the dissection of the localization and roles of new molecules in the axon-Schwann cell unit, including periaxin and connexin32, which are mutated in specific heritable neuropathies; (2) the recognition of the range of phenotypes associated with individual genetic abnormalities, so that the same defects can even produce both demyelinating and axonal forms of heritable neuropathies. The axonal injury associated with demyelination reflects elaborate interactions between axons and Schwann cells. Summary: Demyelinating neuropathies, even those due to abnormalities in intrinsic Schwann cell or myelin proteins, can have clinical manifestations due to distally predominant axonal degeneration.