Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031117 (peripheral neuropathy)
 10,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Charcot-Marie-Tooth disease type 1A is a demyelinating, inherited peripheral neuropathy which is associated with a DNA duplication in chromosome 17p11.2-p12 in over 70% of patients with CMT1A. The CMT1A duplication is not detected cytogenetically, and constitutes a tandem duplication of a 1.5-Mb region of DNA flanked by homologous sequences designated as CMT1A-REP. Detection of the CMT1A duplication by molecular methods is a valuable diagnostic test for the majority of CMT1A cases. This duplication mutation shows stable inheritance through multiple generations, and may also arise as a new mutation in sporadic patients. The CMT1A duplication leads to the disease phenotype apparently through increased dosage of a gene(s) within the duplicated segment. A disease gene associated with CMT1A has been identified in the form of PMP22, which maps within the CMT1A duplication region, and encodes a myelin protein of the peripheral nerve. Point mutations in the PMP22 gene have been identified in CMT1A patients, including one case of a new mutation in PMP22 which coincided with the onset of the disease. Thus, two alternative molecular mechanisms are responsible for CMT1A: DNA duplication leading to increased gene dosage, and point mutation of the PMP22 gene.
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PMID:Charcot-Marie-Tooth disease type 1A: molecular mechanisms of gene dosage and point mutation underlying a common inherited peripheral neuropathy. 1198 69

Charcot-Marie-Tooth disease type 1A is a dominantly inherited demyelinating disorder of the peripheral nervous system. It is most frequently caused by overexpression of peripheral myelin protein 22 (PMP22), but is also caused by point mutations in the PMP22 gene. We describe a new transgenic mouse model (My41) carrying the mouse, rather than the human, pmp22 gene. The My41 strain has a severe phenotype consisting of unstable gait and weakness of the hind limbs that becomes obvious during the first 3 weeks of life. My41 mice have a shortened life span and breed poorly. Pathologically, My41 mice have a demyelinating peripheral neuropathy in which 75% of axons do not have a measurable amount of myelin. We compare the peripheral nerve pathology seen in My41 mice, which carry the mouse pmp22 gene, with previously described transgenic mice over-expressing the human PMP22 protein and Trembler-J (TrJ) mice which have a P16L substitution. We also look at the differences between CMT1A duplication patients, patients with the P16L mutation and their appropriate mouse models.
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PMID:Comparison of a new pmp22 transgenic mouse line with other mouse models and human patients with CMT1A. 1209 Apr 4

Charcot-Marie-Tooth (CMT) disease is the most frequent hereditary peripheral neuropathy in humans. Its prevalence is about one in 2500. A subform, CMT1A, is transmitted as an autosomal dominant trait. An estimated 75% of patients are affected. This disorder has been shown to be associated with the duplication of a 1.5 Mb region of the short arm of chromosome 17, in which the PMP22 gene has been mapped. We have constructed a murine model of CMT1A by inserting into the murine genome a human YAC containing peripheral myelin protein 22 (PMP22) and its flanking controlling elements. We describe the behaviour of the C22 line (seven copies of YAC, 2.1 times PMP22 overexpression) during the myelination process. Electron microscopy, morphometry, electrophysiology, nerve conduction and expression of specific markers (e.g. Krox20) in normal and pathological Schwann cells demonstrated that PMP22 overexpression leads to a defect in the myelination of axons. The largest axons are the most affected. Only a few demyelination/remyelination processes were observed. Moreover, PMP22 overexpression probably enhances collagen synthesis by fibroblasts, before myelination, demonstrating that structures other than Schwann cells are affected by PMP22 overexpression. Classically, CMT1A was thought to be induced by a demyelination process following a phase of normal myelination, yet our data suggest that dysmyelination should be considered as a major factor for the disease.
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PMID:PMP22 overexpression causes dysmyelination in mice. 1224 79

Two genes were identified for autosomal recessive forms of early onset Parkinson's disease: parkin and DJ-1. We describe 2 siblings with EOPD due to parkin mutations and peripheral neuropathy, which presented as neuropathy with liability to pressure palsies (HNPP) in the index case. RT-PCR experiments revealed that the parkin gene is expressed in sural nerves from both controls and patient with parkin-related disease. Our findings support the view that parkin may play a role in the peripheral nervous system.
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PMID:Does parkin play a role in the peripheral nervous system? A family report. 1530 Jun 70

Charcot-Marie-Tooth (CMT) disease is a hereditary demyelinating peripheral neuropathy, and CMT Type 1A is the most common form. In most cases, CMT1A is usually caused by duplication at chromosome 17p11.2-12. Type 2 diabetes mellitus (Type 2 DM) is a common metabolic disorder, characterized by chronic hyperglycemia that can be associated with micro- and/or macrovascular complications. Only a few studies reported CMT1A duplication in association with Type 2 DM. This article explores the characteristics of a large family of 69 members with respect to CMT1A and Type 2 DM. CMT1A was detected in 28 of them. Molecular genetic study was performed in 22, and duplication was detected in all of them. Six of the 22 members with CMT1A also had Type 2 DM based on the American Diabetes Association diagnostic criteria. Association of these two conditions may be coincidental; however, the occurrence of these two diseases in this large family may also suggest a genetic basis. More extensive reports and further investigations of such families having this combination will certainly provide a better understanding of this link.
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PMID:A large family with Charcot-Marie-Tooth Type 1a and Type 2 diabetes mellitus. 1639 77

Charcot-Marie-Tooth [CMT] syndrome is the most common hereditary peripheral neuropathy. CMT1A, which accounts for 50% of all CMT cases, usually results from triploidy of the PMP22 gene. Preclinical trials using an animal model show that disabled mice force-fed with high doses of ascorbic acid partially recover muscular strength after a few months of treatment, and suggest that high doses of ascorbic acid repress PMP22 expression. In this study, we demonstrated that ascorbic acid represses PMP22 gene expression by acting on intracellular cAMP levels and adenylate cyclase activity. This action is dose dependent and specific to ascorbic acid, since repression is not observed after treatment with other antioxidants. The new properties of ascorbic acid are discussed, along with the implications of these findings for CMT disease treatment.
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PMID:Ascorbic acid inhibits PMP22 expression by reducing cAMP levels. 1730 24

We report a 24-year-old male with an unusual combination of two inherited neuromuscular disorders--Charcot-Marie-Tooth (CMT) disease type 1A and Duchenne muscular dystrophy (DMD). A phenotypic presentation of this patient included features of both these disorders. Nerve conduction studies revealed demyelinating peripheral neuropathy. Electromyography showed a profound myogenic pattern. The serum creatine kinase level was highly elevated. Muscle biopsy revealed a dystrophic picture with deficient dystrophin immunostaining. CMT1A duplication on chromosome 17p11.2 was found. The frame-shift mutation c.3609-3612delTAAAinsCTT (p.K1204LfsX11) was detected in the dystrophin gene by analysing mRNA isolated from the muscle tissue. The patient inherited both these mutations from his mother. The combination of CMT1A and DMD has not been reported as yet.
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PMID:Charcot-Marie-Tooth neuropathy type 1A combined with Duchenne muscular dystrophy. 1788 May 76

Charcot-Marie-Tooth (CMT) is a common inherited peripheral neuropathy with a prevalence of 1 in 2,500. CMT has two distinct forms (CMT1 and CMT2) that can be identified electrophysiologically. A 1.5 Mb tandem microduplication including peripheral myelin protein 22 gene (PMP22) on chromosome 17p11.2-12 causes CMT1A. The increased gene dosage effect of PMP22 is thought to be responsible for the pathogenesis of CMT1A. In this study, 39 Turkish CMT1A patients and 60 unrelated control samples had been examined for the duplication using polymorphic short tandem repeat (STR) markers. Seven STR marker sites (AC005838-4A-, AC0013248-9A-, AC0013248-9B-, D17S2218, D17S2220, D17S2227, and D17S2229) on the duplicated region were amplified via polymerase chain reaction, electrophoresed through 8% polyacrilamide gel and evaluated for the duplication. The rate of duplication was 92.3' (36/39) in the patients whereas it was zero in the control samples. Allele distributions, number of alleles and heterozygosity values of more informative markers (D17S2218, D17S2220, D17S2227, and D17S2229) were assessed. It is found that approximately 85% of duplications in Turkish CMT1A patients were depicted by using D17S2220 and D17S2229 markers together.
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PMID:Duplication analysis in Turkish Charcot-Marie-Tooth type 1A patients using short tandem repeat markers. 1791 30

Charcot-Marie-Tooth disease (CMTD) is a hereditary demyelinating peripheral neuropathy clinically presenting with sensory and motor defects, but rarely affecting cardiac function. Long QT syndrome (LQTS) is a congenital or acquired cardiovascular disorder characterized by ventricular depolarization defect. No studies reported CMTD in association with LQTS. We describe a child and his family who had both CMT1A and LQTS.
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PMID:Charcot-Marie-Tooth type 1a in a child with Long QT syndrome. 1879 33

Charcot-Marie-Tooth disease (CMT), also called hereditary motor and sensory neuropathy (HMSN), is the most common inherited peripheral neuropathy, comprised by a group of genetically heterogeneous disorders that share clinical characteristics of progressive distal muscle weakness and atrophy, foot deformities, distal sensory loss, and depressed tendon reflexes. It can be categorized according to its electrophysiological or pathological features, transmission patterns, age of disease onset, and molecular pathology. CMT type 1 (CMT1; MIM 118200) is a group of autosomal dominant-inherited demyelinating neuropathies with a disease onset at or after childhood. Five different subtypes have been identified based on different causative genes. Among them, CMT1A (MIM #118220) is most common and is usually associated with a duplication of a 1.5-Mb region on chromosome 17p11.2, which includes peripheral myelin protein 22 gene (PMP22; MIM *601097). Currently, there is no cure or obviously effective disease-modifying treatment for CMT. Two potential effective therapeutic agents for CMT1A were investigated recently. One is ascorbic acid and another is neurotrophin-3 (NT-3), an important component of the Schwann cell autocrine survival loop. Early diagnosis can facilitate CMT patients to modify their life styles timely for minimizing nerve injury to delay or avoid disability. Molecular diagnosis of CMT can provide the basis for appropriate genetic counseling and further CMT research.
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PMID:[Charcot-Marie-Tooth disease]. 1897 29


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