TOMACULOUS NEUROPATHY - A CLINICAL AND ELECTROPHYSIOLOGICAL STUDY IN PATIENTS WITH AND WITHOUT 1.5-MB DELETIONS IN CHROMOSOME 17P11.2

Tomaculous neuropathy is the descriptive term for the ''sausagelike'' swellings of myelin characteristic of hereditary neuropathy with liabi lity to pressure palsies (HNPP), A 1.5-Mb deletion in chromosome 17p11 .2 is present in the majority but not all cases of HNPP, We reviewed t he clinical and electrophysiological features of 18 patients with toma culous neuropathy and compared these features between patients with an d without the typical large deletion. Patients presented with a variet y of pressure-induced nerve palsies and brachial plexopathies. Two pat ients presented with generalized symmetric sensorimotor polyneuropathi es, Four patients were older than their respective probands but were a s yet asymptomatic. Nerve conduction studies demonstrated prolonged di stal latencies out of proportion to slowing of conduction velocities, suggesting a distally accentuated myelinopathy, DNA analysis revealed the 1.5-Mb deletion in all the familial cases and in 3 of the sporadic patients, The clinical and electrophysiological features were similar between patients with and without the 1.5-Mb deletion in chromosome 1 7p11.2. (C) 1996 John Wiley & Sons, Inc.