Hypertrophic neuropathy is a non-specific consequence of repeated demyelination and remyelination, encountered in a wide range of inherited and acquired disorders. We report an 11-year-old boy with HMSN III, a kind of hypertrophic neuropathy, with clinical, electrophysiologic and pathologic data. The electrophysiologic studies show complete conduction block in the upper and lower extremities with severe abnormal spontaneous activities. The pathologic findings of sural nerve reveal prominent hypomyelination, onion bulb formation, and severe endoneurial collagenization. Complete conduction block with the preservation of fair to good grade muscle strength is an unusual finding in hypertrophic neuropathy and other peripheral neuropathies, in general.
Case Report ; Child ; Hereditary Motor and Sensory Neuropathies/pathology/*physiopathology ; Human ; Hypertrophy ; Male ; *Neural Conduction

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant inherited disorder characterized by recurrent pressure palsies. Most HNPP patients have a 1.5 mb deletion in chromosome 17p11.2-p12. The present study aimed at evaluating the deletion of the 17p11.2-p12 region in Korean subjects with families exhibiting HNPP phenotype, and to determine the clinical, electrophysiological and morphological aspects specifically associated with this deletion in HNPP patients. By genotyping six microsatellite markers (D17S921, D17S955, D17S1358, D17S839, D17S122 and D17S261), HNPP with the deletion was observed in 79% (19 of 24) of HNPP families. Nerve conduction studies were performed in 35 HNPP patients from these 19 families. The observed HNPP deletion frequency in Koreans is consistent with findings in other populations. Disease onset occurred at a significantly earlier age in patients with recurrent pressure palsies than in those with a single attack (P<0.01). Nerve conduction studies demonstrated diffuse mild to moderate slowing of nerve conduction velocities that were worse over the common entrapment sites, regardless of the clinical manifestations. A long duration of compound muscle action potentials without a conduction block or a temporal dispersion is a characteristic of this disease. A sural nerve biopsy with teasing was performed in four patients, and tomacula of the myelin sheath was found in 56.4%. Our findings appear to support the existence of a phenotype/genotype correlation in HNPP patients of Korean ancestry with the deletion, and suggest that HNPP patients with earlier symptom onset face an increased chance of having recurrent attacks.
Adolescent ; Adult ; Age of Onset ; Aged ; Charcot-Marie-Tooth Disease/genetics ; Child ; Child, Preschool ; *Chromosome Deletion ; *Chromosomes, Human, Pair 17 ; DNA Mutational Analysis ; Electrophysiology ; Female ; Genotype ; Hereditary Motor and Sensory Neuropathies/*genetics/pathology/physiopathology ; Humans ; Korea ; Male ; Microsatellite Repeats ; Middle Aged ; Paralysis/*genetics/pathology/physiopathology ; Pedigree ; Phenotype ; Research Support, Non-U.S. Gov't ; Sural Nerve/pathology/physiopathology