Exp Mol Med.  2004 Feb;36(1):28-35.

Hereditary neuropathy with liability to pressure palsies (HNPP) patients of Korean ancestry with chromosome 17p11.2-p12 deletion

• Kim SM
• Chung KW
• Choi BO
• Yoon ES
• Choi JY
• Park KD
• Sunwoo IN

Abstract

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.

Keyword

Charcot-Marie-Tooth disease; hereditary motor and sensory neuropathies; hereditary sensory and autonomic neuroplathies; genotype; microsatellite repeats

MeSH Terms

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