Clinical, electrophysiological and magnetic resonance findings in a family with hereditary neuropathy with liability to pressure palsies caused by a novel PMP22 mutation.
Hereditary neuropathy with liability to pressure palsies (HNPP) is a disorder mainly caused by a 1.5-Mb deletion at 17p11.2-12 (and in some rare cases by point mutations) and clinically associated with recurrent painless palsies. Here, we performed electrophysiological (motor, sensory and terminal latency index), MRI and genetic studies in a family referred for ulnar neuropathy with pain. Surprisingly, we found typical neurophysiological features of HNPP (prolongation of distal motor latencies and diffuse SNCV slowing with significant slowing of motor nerve conduction velocities). Besides, the proband presented conduction block in left ulnar, left median and both peroneal nerves. MRI findings were consistent with an underlying neuropathy. Molecular studies identified a novel frameshift mutation in PMP22 confirming the diagnosis of HNPP. Our data suggest that neurophysiological studies are essential to characterize underdiagnosed HNPP patients referred for peripheral neuropathy. Our experience shows that MRI could be a complementary tool for the diagnosis of these patients.
Department of Clinical Neurophysiology, Hospital Universitario Cruces, Barakaldo, Bizkaia, Spain.
Izaskun
I
Yurrebaso
Osatek Alta Tecnología Sanitaria S.A., Galdakao, Bizkaia, Spain.
Oscar L
OL
Casado
Department of Neurology, Hospital Universitario Cruces, Barakaldo, Bizkaia, Spain.
Joseba
J
Barcena
Molecular (Epi)Genetic Laboratory, Research Unit, Hospital Universitario Araba-Txagorritxu, BioAraba, Vitoria-Gasteiz, Spain.
Guiomar
G
Perez de Nanclares
Research Unit, REDISSEC: Health Services Research on Chronic Patients Network, Hospital Galdakao-Usansolo, Galdakao, Bizkaia, Spain. Electronic address: urko.aguirrelarracoechea@osakidetza.net.
Urko
U
Aguirre
D000328:Adult; D001176:Arthrogryposis / Q000175:diagnosis* / Q000235:genetics; D004568:Electrodiagnosis; D016368:Frameshift Mutation; D015417:Hereditary Sensory and Motor Neuropathy / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009154:Mutation; D009185:Myelin Proteins / Q000235:genetics*
D009185:Myelin Proteins; C073687:PMP22 protein, human
Hereditary neuropathy with liability to pressure palsies; MRI; No recurrent palsies with pain; Novel mutation; PMP22