Charcot-Marie-Tooth disease type 1A (CMT1A) is associated with duplication of chromosome 17p11.2-p12, whereas hereditary neuropathy with liability to pressure palsies (HNPP), which is an autosomal dominant neuropathy showing characteristics of recurrent pressure palsies, is associated with 17p11.2-p12 deletion. An altered gene dosage of PMP22 is believed to the main cause underlying the CMT1A and HNPP phenotypes. Although CMT1A and HNPP are associated with the same locus, there has been no report of these two mutations within a single family. We report a rare family harboring CMT1A duplication and HNPP deletion.
Charcot-Marie-Tooth Disease ; Gene Dosage ; Humans ; Paralysis ; Phenotype

Charcot-Marie-Tooth disease (CMT) is the most common form of hereditary neuropathy with significant clinical and genetic heterogeneity. So far 28 genes have been cloned. The main clinical manifestations of CMT include progressive distal muscle wasting and weakness, impaired distal sensation, and diminishing or loss of tendon reflex. Patients may be classified into demyelinating type (CMT1) and axonal type (CMT2) according to electrophysiological and pathological characteristics. Establishment of a standard diagnostic procedure based on clinical, electrophysiological and pathological findings will enable accurate diagnosis in most CMT patients and provide guidance for gene consulting and prognosis.
Charcot-Marie-Tooth Disease ; classification ; diagnosis ; genetics ; Humans

Charcot-Marie-Tooth X type 1 (CMTX1) is caused by mutations in the connexin 32 gene (Cx32) on the X chromosome. Electrophysiologically, CMTX1 is usually associated with intermediate slowing of conduction velocities and severe impairments in male patients. In addition, patients with CMTX1 rarely present conduction block and temporal dispersion, which are characteristic findings in acquired demyelinating neuropathy. We report herein, for the first time in Korea, two patients with Cx32 mutations who exhibited unusual electrophysiological findings.
Charcot-Marie-Tooth Disease* ; Humans ; Korea ; Male ; X Chromosome

Mutations of the CMT genes develop a variety of distinct phenotypes. Cx32 gene mutations cause the X-linked form of CMT disease, and mutations in EGR2 are associated with CMT type 1, DSS, and congenital hypomyelination neuropathy. Her parents, grandmother and sister did not show the V136A mutation in Cx32. We report the first CMT patient with EGR2 and Cx32 mutations.
Charcot-Marie-Tooth Disease ; Humans ; Parents ; Phenotype ; Siblings

Charcot-Marie-Tooth Disease ; Child, Preschool ; Humans ; Male

No abstract available.
Amyotrophic Lateral Sclerosis* ; Charcot-Marie-Tooth Disease* ; China* ; Pedigree*

Humans ; Charcot-Marie-Tooth Disease/complications* ; Hoarseness/etiology*

We report data on 2 members of a family affected by a dominantly inherited disorder closely resembling Roussy-Levy syndrome(RLS) Electrophysiological findings showed a marked decrease of motor and sensory conduction velocities and mild neurogenic damage. Light and electron microscopy of sural nerve biopsy showed a hypertrophic neuropathy with diffuse onion-bulb formations and marked decrease of large size fibers. Teased fiber preparations revealed reduced internodal lengths and segmental demyelination. The hypothesis that RLS is not a disease entity but a hypertrophic-type of Charcot-Marie Tooth disease with essential tremor(HMSN type 1) is strongly supported.
Biopsy ; Charcot-Marie-Tooth Disease* ; Demyelinating Diseases ; Humans ; Microscopy, Electron ; Sural Nerve ; Tooth Diseases

OBJECTIVETo study the electromyographic and genetic characteristics in children with Charcot-Marie-Tooth disease type 1 (CMT1).

METHODSRoutine electromyography and nerve conduction were performed in 24 children with CMT1. Polymerase chain reaction (PCR) combined with restriction enzyme digestion was used to detect gene duplication on chromosome 17p11.2-12. Ten healthy children served as the control group.

RESULTSThe peripheral nerve conduction velocity slowed or disappeared in all of the 24 patients (100%). The lesions of the sensory nerves were more severe than the motor nerves, and the lesions of the lower limbs were more severe than the upper limbs. Of 72 muscles detected, 40 (56%) showed neurogenic lesions. The older the patients, the more severe the muscle lesions. Specific junction fragments (1760 bp) were identified in 13 (54%) out of 24 patients, but were not identified in the healthy controls.

CONCLUSIONSThe electromyographic changes are characterized by peripheral nerve conduction velocities slowing and neurogenic lesions of muscles in children with CMT1. The PCR combined with restriction enzyme digestion may be a simple and accurate method for gene diagnosis of CMT1.

Adolescent ; Charcot-Marie-Tooth Disease ; genetics ; physiopathology ; Child ; Electromyography ; Female ; Humans ; Male ; Neural Conduction

We report a 15-year-old girl with hereditary neuropathy with liability to pressure palsy (HNPP), whose electrophysiological features mimicked Charcot-Marie-Tooth disease 1A. Her mother was asymptomatic, but a nerve conduction study was compatible with HNPP. Molecular analysis confirmed the deletion of chromosome 17p11.2 in both patients. Our case suggests that HNPP has more diverse electrophysiological features than reported so far.
Adolescent ; Charcot-Marie-Tooth Disease ; Electrodiagnosis ; Female ; Humans ; Mothers ; Neural Conduction ; Paralysis*