Hereditary neuropathy with liability to pressure palsy: a brief review with a case report

Hereditary Neuropathy with Liability to Pressure Palsy (HNPP) is an autosomal dominant disorder and is usually characterized by episodes of recurrent and painless focal motor and sensory peripheral mononeuropathy. This condition is usually localized around areas of entrapment (predominantly the wrists, knees, elbows, and shoulders). The genetic locus of the disease is chromosome 17p12. A deletion of the PMP22 gene results in the lack of peripheral myelin protein, a key component to the myelin sheet of peripheral nerves. However, this disease may be completely asymptomatic until an event, such as a minor trauma, triggers these episodes, as seen in our presented case report. The diagnosis of HNPP can be somewhat challenging, as other diseases, such as Charcot-Marie-Tooth disease type 1A (CMT) and Hereditary Neuralgic Amyotrophy (HNA) must be included in the differential diagnosis due to their overlapping clinical features. There are currently no treatments to cure the disease, but therapies seek to alleviate the symptoms and recurring episodes.