J Reconstr Microsurg 2011; 27(1): 067-074
DOI: 10.1055/s-0030-1267832
© Thieme Medical Publishers

Clinical Implications of Peripheral Myelin Protein 22 for Nerve Compression and Neural Regeneration: A Review

Helen G. Hui-Chou1 , Sharyhar S. Hashemi2 , Ahmet Hoke3 , A. Lee Dellon4
  • 1Division of Plastic and Reconstructive Surgery, Johns Hopkins/University of Maryland Plastic Surgery Program, Baltimore
  • 2Dellon Institute for Peripheral Nerve Surgery, Towson
  • 3Department of Neurology, Johns Hopkins University School of Medicine, Baltimore
  • 4Department of Plastic Surgery and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Publication History

Publication Date:
25 October 2010 (online)

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ABSTRACT

Peripheral myelin protein 22 (PMP22) is a major component of the peripheral myelin sheath. The PMP22 gene is located on chromosome 17p11.2, and defects in PMP22 gene have been implicated in several common inherited peripheral neuropathies. Hereditary neuropathy with liability to pressure palsies (HNPP), Charcot-Marie Tooth disease type 1A (CMT1A), Dejerine-Sottas syndrome, and congenital hypomyelinating neuropathy are all associated with defects in PMP22 gene. The disease phenotypes mirror the range of expression of PMP22 due to the corresponding genetic defect. HNPP, characterized by a milder recurrent episodic focal demyelinating neuropathy, is attributed to a deletion leading to PMP22 underexpression. On the other end of the spectrum, CMT1A leads to a more uniform demyelination and axonal loss, resulting in severe progressive distal weakness and paresthesias; it is due to a duplication at 17p11.2 leading to PMP22 overexpression. Additional point mutations result in varying phenotypes due to dysfunction of the resultant PMP22 protein. All inherited neuropathies are diagnosed with a combination of physical findings on examination, electromyography, sural nerve biopsies, and genetic testing. Treatment and management of these disorders differ depending on the underlying genetic defect, nerves involved, and resulting functional impairments. A review of current literature elucidates clinical, microsurgical implications, and management of patients with PMP22-related neuropathy.

REFERENCES

A. Lee DellonM.D. Ph.D. 

Professor, The Exchange Building, Suite 18

1122 Kenilworth Drive, Towson, MD 21204

Email: aldellon@dellon.com