Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1762617 (weakness)
 37,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The most common form of autosomal recessive (AR) hereditary inclusion-body myopathy (HIBM), originally described in Persian-Jewish families, is characterized by onset in early adult life with weakness and atrophy of distal lower limb muscles, which progress proximally and relatively spare the quadriceps. AR HIBM is associated with mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase gene (GNE) on chromosome 9p12-13. In the present study we have identified seven novel GNE mutations in patients from five unrelated Italian families with clinical and pathologic features indicative of AR HIBM. Four were missense mutations (c.1556A>G [p.N519S], c.79C>T [p.P27S], c.1798G>A [p.A600T] and c.616G>A [p.G206S]), two consisted in a single-base deletion (c.616delG [p.G206fsX4] and c.1130delT [p.I377fsX16]) and one in an intronic single-base insertion (c.1070+2dupT). These latter findings further extend the type of GNE mutations associated with HIBM. Furthermore, in one patient we also identified the c.737G>A [p.R246Q] missense mutation that corresponds to the one previously reported in a family from the Bahamas. Interestingly, in two of our families distinct mutations affected nucleotide c.616 in exon 3 (c.616delG and c.616G>A). The possibility of specific portions of the gene being more prone to mutations remains to be elucidated.
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PMID:Novel GNE mutations in Italian families with autosomal recessive hereditary inclusion-body myopathy. 1514 76

Hereditary inclusion body myopathy (HIBM) is a unique group of neuromuscular disorders characterized by adult-onset, slowly progressive distal and proximal muscle weakness, which is caused by mutations in UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE), the key enzyme in the biosynthetic pathway of sialic acid. In order to investigate the consequences of the mutated GNE enzyme in muscle cells, we have established cell cultures from muscle biopsies carrying either kinase or epimerase mutations. While all myoblasts carrying a mutated GNE gene show a reduction in their epimerase activity, only the cells derived from the patient carrying a homozygous epimerase mutation present also a significant reduction in the overall membrane bound sialic acid. These results indicate that although mutations in each of the two GNE domains result in an impaired enzymatic activity and the same HIBM phenotype, they do not equally affect the overall sialylation of muscle cells. This lack of correlation suggests that the pathological mechanism of the disease may not be linked solely to the well-characterized sialic acid pathway.
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PMID:No overall hyposialylation in hereditary inclusion body myopathy myoblasts carrying the homozygous M712T GNE mutation. 1567 Jul 73

Distal myopathy with rimmed vacuoles (DMRV) and hereditary inclusion body myopathy (hIBM) share similar clinical features, including onset in young adulthood with preferential involvement of the anterior compartment of the lower legs and sparing of the quadriceps femoris muscles. The most significant muscle pathology is the presence of rimmed vacuoles, which appear to play a major role in muscle atrophy and weakness. After the discovery of the gene locus in both DMRV and hIBM on chromosome 9 and mutations in the gene encoding the enzyme UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE), it became clear that they are allelic disorders. From gene analysis, it is evident that these diseases are not restricted to people of Japanese and Jewish ancestry, but that they are widely distributed throughout all ethnic groups. Although defective glycosylation to a muscle fiber has been suggested, the mechanism by which myofibrillar degeneration is followed by rimmed vacuole formation remains to be clarified.
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PMID:Distal myopathy with rimmed vacuoles and hereditary inclusion body myopathy. 1567 10

Autosomal recessive hereditary inclusion body myopathy (AR-HIBM), with sparing of the quadriceps, is characterized by adult-onset, with weakness and atrophy of distal lower limb muscles, and typical histopathological findings in muscle biopsy. AR hIBM is associated with mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene on chromosome 9p12-13 . We report two unrelated Tunisian families with clinical and pathological features of AR HIBM. One distinct homozygous GNE missense mutation, M712T, previously reported in Middle Eastern Jewish patients, and a newly identified one, L379H, were found in one patient from each family. We conclude that AR HIBM in Tunisia shows an allelic genetic heterogeneity.
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PMID:Allelic heterogeneity of GNE gene mutation in two Tunisian families with autosomal recessive inclusion body myopathy. 1583 30

Distal myopathy with rimmed vacuoles (DMRV) or hereditary inclusion body myopathy (hIBM) is an autosomal recessive disorder clinically characterized by weakness that initially involves the distal muscles, although other muscles can be affected as well. Pathological hallmarks include the presence of rimmed vacuoles (RVs) and intracellular Congo red-positive depositions in vacuolated or nonvacuolated fibers. Mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene, which encodes the rate-limiting enzyme in sialic acid biosynthesis, are causative of DMRV/hIBM. Recently, we have generated a mouse model (Gne(-/-)hGNEV572L-Tg) for this disease, and have shown that these mice exhibit hyposialylation and intracellular amyloid deposition before the characteristic RVs are detected, indicating that autophagy is a downstream phenomenon to hyposialylation and amyloid deposition in DMRV/hIBM.
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PMID:Autophagy in a mouse model of distal myopathy with rimmed vacuoles or hereditary inclusion body myopathy. 1716 66

Distal myopathy with rimmed vacuoles (DMRV), also called hereditary inclusion body myopathy (hIBM), is characterized clinically by weakness and atrophy that initially involves the distal muscles and pathologically by the presence of rimmed vacuoles (RVs) or intracellular protein deposits in myofibers. It is caused by mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene that is important in sialic acid synthesis. Recently, we generated a mouse model (Gne(-/-)hGNED176VTg) that exhibits muscle weakness and pathological changes similar to DMRV patients. To gain better understanding of the pathomechanism of DMRV, we determined temporal changes in the overall motor performance of this model mouse for DMRV in correlation with the structure and function of isolated skeletal muscles and muscle pathology. These DMRV mice exhibited muscle weakness, decreased whole muscle mass and cross-sectional area (CSA), and reduced contractile power in an age-related manner. Single-fiber CSA further supported the finding of muscle atrophy that involved both type I and type II fibers. These results suggest that atrophy is highly correlated with reduced production of force at young age, both in vivo and ex vivo, thereby implicating the important role of atrophy in the pathomechanism of DMRV. In older age, and particularly in gastrocnemius muscles, RVs and intracellular inclusions were seen in type IIA fibers, further aggravating reduction of force and specific increase in twitch-tetanus ratio.
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PMID:Muscle weakness correlates with muscle atrophy and precedes the development of inclusion body or rimmed vacuoles in the mouse model of DMRV/hIBM. 1862 37

Distal myopathy with rimmed vacuoles (DMRV) or hereditary inclusion body myopathy (hIBM) is an adult onset slowly progressive myopathy secondary to mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene that encodes a bifunctional enzyme which catalyzes the rate-limiting step in sialic acid biosynthesis. Many hypotheses have been proposed to explain why patients develop weakness and atrophy, but are most views are obscure and thus are still considered controversial, partly because of the lack of an appropriate model with which these theories could be clarified. In this review, we briefly summarize the progress in DMRV research, and highlight efforts of researchers in generating the animal model for this myopathy.
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PMID:Perspectives on distal myopathy with rimmed vacuoles or hereditary inclusion body myopathy: contributions from an animal model. Lack of sialic acid, a central determinant in sugar chains, causes myopathy? 1864 67

Homozygous mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene cause hereditary inclusion body myopathy type 2 (HIBM2). We describe two unrelated American patients with novel GNE mutations. While one patient followed a typical disease course for HIBM2 with an onset at age 25 and rimmed vacuole pathology on muscle biopsy, the second patient had several features atypical for HIBM2. This patient's onset was at age 55, included distal weakness, quadriceps sparing and respiratory insufficiency. His muscle biopsy showed prominent necrosis without rimmed vacuoles. This study expands the phenotype and illustrates the clinical spectrum of HIBM2 identified in a U.S. based neuromuscular clinic.
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PMID:Novel GNE mutations in two phenotypically distinct HIBM2 patients. 2113 Dec

Distal myopathy with rimmed vacuoles (DMRV), also called hereditary inclusion body myopathy (hIBM), is a moderately progressive hereditary muscle disorder affecting young adults. DMRV/hIBM is characterized clinically by muscle atrophy and weakness initially involving the distal muscles, and pathologically by the presence of small angular fibers, formation of rimmed vacuoles and deposition of various proteins in the muscle fibers. This disease is known to be caused by mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase gene, which encodes the essential enzyme in sialic acid biosynthesis, leading to a reduction of sialic acid levels in the serum and skeletal muscles of affected patients. As it is a metabolic disease, metabolite supplementation is theoretically one of the therapeutic options. In this review, recent animal models for DMRV/hIBM are briefly characterized followed by a focus on the administration of sialic acid metabolites as a reliable therapeutic option to DMRV/hIBM with the following points highlighted: the property of compounds, the pharmacokinetic metabolism in vivo, and the therapeutic effects on the DMRV/hIBM mouse model.
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PMID:A preclinical trial of sialic acid metabolites on distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy, a sugar-deficient myopathy: a review. 2117 5

Hereditary inclusion body myopathy (HIBM) is a young-adult onset autosomal recessive disorder caused by a hypomorphic rate limiting enzyme of sialic acid biosynthesis. The enzyme is UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase, and is encoded by the GNE gene. HIBM causes slowly progressive muscle weakness and atrophy. Patients are typically diagnosed at 20-30 years of age, and most patients are incapacitated and wheelchair-confined by 30-50 years of age. Some sialic acid containing glycoproteins, including neural cell adhesion molecule (NCAM), are hyposialylated in HIBM muscle biopsy samples. We developed a method to allow detection of serum NCAM sialylation using Western blot, and tested serum samples from several patients and a HIBM mouse model. Preliminary results showed a clear difference in polysialylated and hyposialylated forms of NCAM extracted from serum, and showed NCAM is hyposialylated in HIBM serum samples. This initial finding may prove useful in reducing the need for serial muscle biopsies in HIBM treatment trials. Additional studies are underway to further validate this finding and to evaluate the specificity, reliability, and robustness of this potential serum biomarker for HIBM.
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PMID:Serum neural cell adhesion molecule is hyposialylated in hereditary inclusion body myopathy. 2208 95


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