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Hereditary neuropathy with liability to pressure palsies

Reviewed April 2007

What is hereditary neuropathy with liability to pressure palsies?

Hereditary neuropathy with liability to pressure palsies is a disorder that affects peripheral nerves. These nerves connect the brain and spinal cord to muscles as well as sensory cells that detect touch, pain, and temperature. In people with this disorder, the peripheral nerves are unusually sensitive to pressure.

Hereditary neuropathy with liability to pressure palsies causes recurrent episodes of numbness, tingling, and/or loss of muscle function (palsy). An episode can last from several minutes to several months, but recovery is usually complete. Repeated incidents, however, can cause permanent muscle weakness or loss of sensation. This disorder is also associated with pain in the limbs, especially the hands.

A pressure palsy episode results from problems in a single nerve, but any peripheral nerve can be affected. Episodes often recur, but not always at the same site. The most common problem sites involve nerves in wrists, elbows, and knees. Fingers, shoulders, hands, feet, and the scalp can also be affected. Many people with this disorder experience carpal tunnel syndrome when a nerve in the wrist (the median nerve) is involved. Carpal tunnel syndrome is characterized by numbness, tingling, and weakness in the hand and fingers. An episode in the hand may affect fine motor activities such as writing, opening jars, and fastening buttons. An episode in the leg can make walking, climbing stairs, or driving difficult or impossible.

Symptoms usually begin during adolescence or early adulthood but may develop anytime from childhood to late adulthood. Symptoms vary in severity; many people never realize they have the disorder, while some people experience prolonged disability. Hereditary neuropathy with liability to pressure palsies does not affect life expectancy.

How common is hereditary neuropathy with liability to pressure palsies?

Hereditary neuropathy with liability to pressure palsies is estimated to occur in 2 to 5 per 100,000 individuals.

What genes are related to hereditary neuropathy with liability to pressure palsies?

Mutations in the PMP22 gene cause hereditary neuropathy with liability to pressure palsies.

Hereditary neuropathy with liability to pressure palsies is caused by the loss of one copy of the PMP22 gene or alterations within the gene. The consequences of PMP22 mutations are not clearly understood. Most likely, PMP22 mutations affect myelin, the protective substance that covers nerve cells. As a result of these mutations, some of the protective myelin covering may become unstable, which leads to increased sensitivity to pressure on the nerves.

How do people inherit hereditary neuropathy with liability to pressure palsies?

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Where can I find information about treatment for hereditary neuropathy with liability to pressure palsies?

You may find information on treatment or management of hereditary neuropathy with liability to pressure palsies or some of its symptoms in the links below, particularly the links for Gene Reviews, MedlinePlus Encyclopedia, Educational resources, and Patient support.

Where can I find additional information about hereditary neuropathy with liability to pressure palsies?

You may find the following resources about hereditary neuropathy with liability to pressure palsies helpful. These materials are written for the general public.

  • MedlinePlus - Health information
    • Encyclopedia: carpal tunnel syndrome (http://www.nlm.nih.gov/medlineplus/ency/article/000433.htm)
    • Health Topic: Carpal Tunnel Syndrome (http://www.nlm.nih.gov/medlineplus/carpaltunnelsyndrome.html)
  • Educational resources - Information pages
    • Ask the Geneticist: inheritance and genetic testing (http://www.askthegen.org/question.php?question_id=384)
    • Jack Miller Center for Peripheral Neuropathy, University of Chicago (http://millercenter.uchicago.edu/learnaboutpn/typesofpn/hereditary/hnpp.shtml)
    • Merck Manual of Medical Information, Second Home Edition (http://www.merck.com/mmhe/sec06/ch095/ch095i.html#sec06-ch095-ch095i-1522)
    • Orphanet (http://www.orpha.net//consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=640)
  • Patient support - For patients and families
    • Charcot-Marie-Tooth Association (http://www.charcot-marie-tooth.org/about_cmt/hnpp.php)
    • The Neuropathy Association (http://www.neuropathy.org)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

  • Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=hnpp)
  • Gene Tests - DNA tests ordered by healthcare professionals (http://www.genetests.org/query?testid=2943)
  • ClinicalTrials.gov - Linking patients to medical research (http://clinicaltrials.gov/search/condition=%22hereditary+neuropathy+with+liability+to+pressure+palsies%22)
  • PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=PubMed&term=(Hereditary+Motor+and+Sensory+Neuropathies[MAJR])+AND+((hnpp[TIAB])+OR+(tomaculous+neuropathy[TIAB]))+AND+english[la]+AND+human[mh]&orig_db=PubMed&filters=ON&pmfilter_EDatLimit=1800+Days)
  • OMIM - Genetic disorder catalog (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=162500)

What other names do people use for hereditary neuropathy with liability to pressure palsies?

  • compression neuropathy
  • entrapment neuropathy
  • familial pressure sensitive neuropathy
  • hereditary motor and sensory neuropathy
  • hereditary pressure sensitive neuropathy
  • HNPP
  • inherited tendency to pressure palsies
  • tomaculous neuropathy

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about hereditary neuropathy with liability to pressure palsies?

  • See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.
  • Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).
  • Submit your question to Ask the Geneticist (http://www.askthegen.org/).

What glossary definitions help with understanding hereditary neuropathy with liability to pressure palsies?

autosomal ; autosomal dominant ; carpal tunnel syndrome ; cell ; compression ; familial ; gene ; median nerve ; motor ; mutation ; nerve cell ; neuropathy ; palsy ; peripheral ; peripheral nerves ; sensitivity ; sensory cells ; sensory neuropathy ; symptom ; syndrome

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://ghr.nlm.nih.gov/glossary).

References
  • Chance PF. Genetic evaluation of inherited motor/sensory neuropathy. Suppl Clin Neurophysiol. 2004;57:228-42. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=16106622)
  • Chance PF. Inherited focal, episodic neuropathies: hereditary neuropathy with liability to pressure palsies and hereditary neuralgic amyotrophy. Neuromolecular Med. 2006;8(1-2):159-74. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=16775374)
  • Chance PF. Overview of hereditary neuropathy with liability to pressure palsies. Ann N Y Acad Sci. 1999 Sep 14;883:14-21. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=10586225)
  • Gene Review: Hereditary Neuropathy with Liability to Pressure Palsies (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=hnpp)
  • Li J, Krajewski K, Lewis RA, Shy ME. Loss-of-function phenotype of hereditary neuropathy with liability to pressure palsies. Muscle Nerve. 2004 Feb;29(2):205-10. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=14755484)
  • van de Wetering RA, Gabreels-Festen AA, Timmerman V, Padberg GM, Gabreels FJ, Mariman EC. Hereditary neuropathy with liability to pressure palsies with a small deletion interrupting the PMP22 gene. Neuromuscul Disord. 2002 Oct;12(7-8):651-5. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=12207933)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: April 2007
Published: May 4, 2009