Clinical and neurophysiological features of the hereditary neuropathy with liability to pressure palsy due to the 17p11.2 deletion

The hereditary neuropathy with liability to pressure palsies (HNPP) is an autossomal dominant disorder manifesting recurrent mononeuropathies. Objective: Evaluate its clinical and nerve conduction studies (NCS) characteristics, searching for diagnostic particularities. Method: We reviewed the neurological manifestations of 39 and the NCS of 33 patients. Results: Family history was absent in 16/39 (41%). The onset complaints were weakness in 24, pain in 6, sensory deficit in 5 and paresthesias in 4. Pain was seen in 3 other patients. The following neuropathy patterns were found: multiple mononeuropathy (26), mononeuropathy (7), chronic sensorimotor polyneuropathy (4), chronic sensory polyneuropathy (1) and unilateral brachial plexopathy (1). NCS showed a sensorimotor neuropathy with focal conduction slowing in 31, two had mononeuropathy and another brachial plexopathy. Conclusion: HNPP presentation is variable and may include pain. The most frequent pattern is of an asymmetrical sensory and motor neuropathy with focal slowing at specific topographies on NCS.