Clinical, Electrophysiological, Pathological And Genomic Study Of Hereditary Neuropathy With Liability To Pressure Palsies

Hereditary neuropathy with liability to pressure palsies (HNPP) is a rare autosomal dominant inherited disease characterized by recurrent painless focal neuropathy precipitated by compression or trauma. It develops in childhood or adolescence, and causes attacks of numbness and weakness. Electrophysiological studies show generalized neuropathy with decreased conduction velocities. The histopathological feature has been found to be "sausage-like" tomaculous changes of myelin sheath. Most patients have a 1.5-megabase deletion on chromosome 17pl 1.2 where the Peripheral Myelin Protein 22 (PMP22) gene is located.Objective The clinical, electrophysiological, pathological features and genomic study of hereditary neuropathy with liability to pressure palsies were performed to explore the routine methods that can be easily used in clinic to detect HNPP and promote the understanding and diagnostic acuity of the disease. Methods 5 cases of HNPP underwent detailed clinical examinations. Motor and sensory condution velocity , distal motor latency, and electromyogram were recorded in clinical affected or unaffected nerves. Sural nerve biopsies were performed for two cases and specimens were treated by HE and Masson staining , observed under light microscope and electron microscope respectively. Polymerase chain reaction(PCR) combined with restricion enzyme digestion were used to detect gene deletion on chromosome 17p11.2 in HNPP patients. Results 3 patients came from one family and it was consistent with autosomal dominant inheritance. Age at onset was in the first or second decade. The clinical features were weakness, numbness as recurrent mononeuropathy precipitated by trivial traumas. Symptoms often disappeared spontaneously after a few days or a few...