Hereditary neuropathy with liability to pressure palsy (HNPP) is a disorder that affects peripheral nerves. This condition 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. The most common problem sites involve nerves in wrists, elbows, and knees. 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. This condition is caused by the loss of one copy of the PMP22 gene or alterations within the gene. It is inherited in an autosomal dominant manner.
The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
|Signs and Symptoms||Approximate number of patients (when available)|
|Decreased nerve conduction velocity||90%|
|Abnormality of the voice||7.5%|
|Cranial nerve paralysis||7.5%|
|Autosomal dominant inheritance||-|
|Segmental peripheral demyelination/remyelination||-|
|Vocal cord paralysis||-|
Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.
There is no specific treatment for hereditary neuropathy with liability to pressure palsy. Treatment is based on an individual's symptoms. Some people with this condition use braces, such as a wrist splint or ankle-foot orthosis (AFO). Protective pads worn at the elbows or knees may prevent pressure and trauma to local nerves. Activities to avoid include prolonged sitting with legs crossed, occupations requiring repetitive movements of the wrist, prolonged leaning on elbows, and rapid weight loss. Vincristine, commonly used in the treatment of lymphoma, has been reported to worsen the symptoms of hereditary neuropathy with liability to pressure palsy. Surgical decompression of nerves remains a controversial treament for this condition.
Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.
Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question
What treatments are available for hereditary neuropathy with liability to pressure palsy? See answer