The diagnosis of a hereditary neuropathy is usually suggested with the early onset of neuropathic symptoms, especially when a positive family history is also present. Prior to the recent genetic advances, the diagnosis was supported by typical findings of marked slowing of the nerve conduction studies on electromyography and a nerve biopsy. Typical findings on a nerve biopsy include the presence of so-called onion-bulbs, indicating a recurring demyelinating and remyelinating of the nerve fibers. With the most recent genetic advances, two major hereditary neuropathies known as "Charcot-Marie-Tooth disease" and "hereditary neuropathy with liability to pressure palsies" can be diagnosed with a simple blood test that identifies the different mutations responsible for these two entities.
There is no effective treatment for hereditary neuropathies. A patient with hereditary neuropathy with liability to pressure palsy (HNPP) must avoid application of pressure to the peripheral nerves as it may result in the nerve palsy.