1/59. Phenotypic variation of a new P0 mutation in genetically identical twins.We have identified a new point mutation in the myelin protein zero (P0) gene in two genetically identical twins with a demyelinating neuropathy. The G to A transition at nucleotide position 382 caused an aspartic acid to asparagine substitution in exon 3. Moreover, we found clear clinical differences which were most evident at an early age. These observations suggest that the expression of this P0 mutation may be susceptible to external, non-genetic influences that may act early in the course of the disease to alter the phenotype.- - - - - - - - - - ranking = 1keywords = demyelinating (Clic here for more details about this article) |
2/59. Demyelinating X-linked charcot-marie-tooth disease: unusual electrophysiological findings.X-linked charcot-marie-tooth disease (CMT-X) is caused by mutations of connexin-32 (Cx-32), which encodes a gap-junction protein. Whether the neuropathy is primarily demyelinative or axonal remains to be established. We report findings of prominent demyelination in a 71-year-old woman with late-onset disease. Electrophysiological studies revealed a nonuniform slowing of motor conduction velocities and dispersion of compound action potentials indicative of a demyelinating process which was confirmed by nerve biopsy. Such electrophysiological features are unusual in hereditary neuropathies and are more commonly found with acquired chronic demyelinating neuropathies. A systematic search confirmed the molecular genomic diagnosis of CMT-X, illustrating the value of such tests in sporadic cases. Severity of clinical symptoms and signs may vary with age and sex of the patient. The pathology of CMT-X in other reported cases has been variably interpreted as axonal, demyelinating, or showing both features. Our observations emphasize the demyelinative nature.- - - - - - - - - - ranking = 3keywords = demyelinating (Clic here for more details about this article) |
3/59. Autosomal recessive hereditary motor and sensory neuropathy with focally folded myelin sheaths (CMT4B).Hereditary motor and sensory neuropathy with focally folded myelin sheaths, or Charcot-Marie-Tooth neuropathy type 4B (CMT4B), is a distinct clinical and genetic entity belonging to the heterogeneous group of autosomal recessive demyelinating neuropathies. We first described a large inbred pedigree with 10 patients affected by CMT4B, which enabled us to uncover the genetic findings, clinical spectrum, and natural history of such a disorder. The clinical picture was characterized by infantile onset with progressive symmetric distal and proximal muscular weakness. Using homozygosity mapping and haplotype sharing analysis, we found evidence of linkage of chromosome 11q23. We then identified a second unrelated family in which two individuals were affected with CMT4B. Although the clinical findings were similar to those previously reported, we excluded the disease locus segregating in this smaller pedigree from the 11q23 region. We thus provided evidence for a second locus causing the CMT4B phenotype. All these findings indicate that CMT4B seems to be phenotypically quite homogeneous, but is genetically heterogeneous.- - - - - - - - - - ranking = 1keywords = demyelinating (Clic here for more details about this article) |
4/59. Acute disseminated encephalomyelitis in a female with hereditary neuropathy with susceptibility to pressure palsy.A 7-year-old female presented with fever, urinary incontinence, mental regression, gait disturbance, and lethargy after diarrhea. magnetic resonance imaging revealed multifocal T(2)-weighted hypersignal lesions supportive of acute disseminated encephalomyelitis. Her mother had been diagnosed with hereditary neuropathy with susceptibility to pressure palsy. The girl was also determined to have hereditary neuropathy with liability to pressure palsy, with a 1.5-Mb deletion in chromosome 17p11.2 encompassing the gene for peripheral myelin protein 22 detected by fluorescent in situ hybridization. Hereditary peripheral neuropathies may be a factor in triggering the autoimmune demyelinating disorder of the central nervous system.- - - - - - - - - - ranking = 1keywords = demyelinating (Clic here for more details about this article) |
5/59. Screening for Charcot-Marie-Tooth type 1A and hereditary neuropathy with liability to pressure palsy in archival nerve biopsy samples by direct-double-differential PCR.Chromosomal imbalance of the peripheral myelin protein-22 gene (PMP22) is known to be the most frequent genetic abnormality in charcot-marie-tooth disease type 1 (CMT1) and hereditary neuropathy with liability to pressure palsy (HNPP). We applied a new quantitative PCR method, the direct-double-differential PCR (dddPCR), to the gene dosage determination of PMP22. The method allows the quantification of the PMP22 gene copy number independently from dna fragmentation, even in highly degraded DNA from up to 12-year-old sural nerve biopsy samples. Chromosomal imbalance of the PMP22 gene, which had been detected by examination of four microsatellites located directly adjacent to the PMP22 gene, between the CMT1A-repetition (CMT1A-REP) elements was reliably confirmed by the dddPCR. Using this method we unexpectedly identified two cases with PMP22 imbalance, although morphologically the neuropathies were of a neuronal or axonal type and not of a demyelinating type as usual. One sural nerve biopsy was from a 58-year-old male diabetes mellitus patient with a disproportionately severe polyneuropathy showing a heterozygous duplication of PMP22. The second biopsy exhibiting a heterozygous deletion of PMP22 was from a 58-year-old female patient with a more axonal than demyelinating type of neuropathy without typical tomaculous changes seemingly altered by exogenous, possibly traumatic factors other than diabetes mellitus. Thus, the dddPCR provides a fast and reliable diagnostic tool for the screening and identification of CMTIA and HNPP cases, which is fast and may be essential even when nerve biopsies show morphologically atypical changes.- - - - - - - - - - ranking = 2keywords = demyelinating (Clic here for more details about this article) |
6/59. charcot-marie-tooth disease and sleep apnoea syndrome: a family study.BACKGROUND: Charcot-Marie-Tooth (CMT) disease is a genetically heterogeneous group of hereditary motor and sensory polyneuropathies in which sleep apnoea has rarely been reported and no causal relation shown. We looked for an association between the most common subtype of CMT disease (CMT1A) and sleep apnoea syndrome. methods: Having diagnosed sleep apnoea and CMT in one family member (index case), we prospectively investigated 13 further members not previously suspected of having neuropathy or apnoeas. All had a neurological examination, electroneuromyography, polysomnography, and genetic testing for CMT disease. FINDINGS: 11 of the 14 family members had the autosomal dominant demyelinating form of CMT disease with PMP22 gene duplication on chromosome 17. Whatever their neurological disability, all 11 individuals had sleep apnoea syndrome with a mean (SD) apnoea-hypopnoea index of 46.6/h (28.5) of sleep (normal value <15/h). The remaining three family members were free from neuropathy and sleep apnoea syndrome. sleep apnoea and neuropathy severity were highly correlated; the compound muscle action potential (CMAP) amplitude of the median nerve was inversely correlated with the apnoea-hypopnoea index (r=-0.69, p=0.029). The severity of neuropathy and sleep apnoea were higher in male CMT individuals and were correlated with age and body mass index. No wake or sleep diaphragmatic dysfunction was shown. INTERPRETATION: We think that sleep apnoea syndrome is related to a pharyngeal neuropathy. Upper airway dysfunction, previously described in the CMT2C subtype, might be a clinical expression of the CMT1A subtype, to which familial susceptibility could predispose.- - - - - - - - - - ranking = 1keywords = demyelinating (Clic here for more details about this article) |
7/59. Inflammatory pathological changes in a 2-year-old boy with charcot-marie-tooth disease.We report histopathological findings in a 2-year-old boy with Charcot-Marie-Tooth (CMT) 1A, which had some similarities to those of chronic inflammatory demyelinating polyneuropathy. These findings are unusual in adult CMT patients but are reported in some patients with corticosteroid-responsive hereditary motor and sensory neuropathy (HMSN) that are characterized by rapid worsening of symptoms. We administered betamethasone based on the inflammatory pathological features but no improvement was seen. Active demyelination is also reported as an early morphological feature in HMSN. It is probable that edema, active demyelination and a few onion bulb formations, which were recognized in this patient, are characteristic early histological changes of HMSN rather than those of corticosteroid-responsive HMSN.- - - - - - - - - - ranking = 3.7758885059763keywords = chronic inflammatory demyelinating, demyelinating, inflammatory demyelinating (Clic here for more details about this article) |
8/59. Chronic inflammatory demyelinating polyneuropathy caused by hiv infection in a patient with asymptomatic CMT 1A.It is well known that patients with Charcot-Marie-Tooth (CMT) disease are liable to present with episodes of cortisone-responsive demyelination, and a superimposed inflammatory component has been suggested. We report a patient who presented with a chronic inflammatory demyelinating polyneuropathy due to a recent hiv infection, which revealed a previously asymptomatic CMT 1A disease documented by identification of the characteristic duplication on the p11.2 region of chromosome 17. The inflammatory process was characterized by pathologic findings on a superficial peroneal nerve biopsy, and the patient improved significantly after corticotherapy. This report gives support to the hypothesis of a genetic susceptibility to inflammatory demyelinating processes in certain CMT kindreds.- - - - - - - - - - ranking = 12.984865424814keywords = chronic inflammatory demyelinating, demyelinating, inflammatory demyelinating (Clic here for more details about this article) |
9/59. Charcot-Marie-Tooth type X: A novel mutation in the Cx32 gene with central conduction slowing.charcot-marie-tooth disease (CMT) is characterized by distal muscle weakness and wasting, often resulting in foot deformities and gait disturbances, distal sensory impairment and by more or less typical changes in sural nerve biopsy. CMT type 1 is also characterized by reduced nerve conduction velocities. For these demyelinating subtypes, most frequently a 1.5 Mb tandem duplication in chromosome 17p11.2-12 comprising the gene for the peripheral myelin protein 22 (PMP22) is observed (CMT1A), but point mutations in PMP22 have also rarely been reported. X-linked, dominant CMTX1 disease is the second most common type of these hereditary motor and sensory neuropathies (HMSN). Mutations in the X chromosomal gene Connexin32 (Cx32) synonymous gap junction beta-1 (GJB1) are detectable in most X-linked CMT families. We report a novel missense mutation--Tyr65His--in the first extracelullar domain of the Cx32 gene in a Czech CMTX1 family. The mutation was not detectable in 50 healthy controls. The clinical phenotype in both the male proband and his mother was moderate with pronounced peroneal weakness and foot drop. Nerve conduction velocities were intermediately decreased (31-38 m/s) in both patients and slowing of central acoustic conduction (BAEP) was found in both the son and the mother whereas visual central conduction slowing (VEP) was detectable only in the son.- - - - - - - - - - ranking = 1keywords = demyelinating (Clic here for more details about this article) |
10/59. Phenotypic variation of a novel nonsense mutation in the P0 intracellular domain.Mutations in the gene for the peripheral myelin protein zero (P0, MPZ) cause type 1B of Charcot-Marie-Tooth sensorimotor neuropathy (CMT1B). Here we report a German family with a novel heterozygous P0 nonsense mutation (G206X) that supposedly removes four-fifths of the amino acid residues constituting the P0 intracellular domain. The 12-year-old propositus had childhood-onset CMT1B associated with bilateral pes cavus, moderate lower limb weakness, and mildly reduced sensory qualities in the distal legs. The electrophysiology was consistent with a demyelinating neuropathy. He inherited the mutation from his mother who had no complaints but slight pes cavus deformity and slow nerve conduction velocities (NCV). Conclusively, truncating mutations within the P0 intracellular domain do not necessarily cause a severe phenotype such as Dejerine-Sottas syndrome (DSS) or congenital hypomyelinating neuropathy (CHN), but can result in mild or moderate CMT1B with intrafamilial clinical variability.- - - - - - - - - - ranking = 1keywords = demyelinating (Clic here for more details about this article) |
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