Clinical, electrophysiological and molecular findings in early onset hereditary neuropathy with liability to pressure palsy

Introduction: The first episode of hereditary neuropathy with liability to pressure (HNPP) in childhood is rare.

Material and Methods: We analyzed retrospectively the data of 7 patients with a deletion in PMP22 and onset of symptoms before age 18 years. Direct sequencing of the LITAF gene was performed in patients and family members.

Results: Clinical presentations varied from mononeuropathies to brachial plexopathy, with recurrent episodes in 4 patients. Electrophysiological abnormalities characteristic for HNNP were found in most subjects. Analysis of the LITAF gene revealed an Ile92Val polymorphism in 6 of 7 (86%) probands and 5 of 7 (83%) family members, over 4 greater frequency than in the general population.

Conclusion: Clinical suspicion of HNPP even when nerve conduction study results do not fulfill HNPP criteria should indicate genetic testing. In our patients early-onset HNPP was associated frequently with Isoleucine 92valine LITAF polymorphism. 

Muscle & Nerve 2014