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)

Pompe's disease is a neuromuscular disorder caused by deficiency of lysosomal acid alpha-glucosidase. Recombinant human alpha- glucosidase is under evaluation as therapeutic drug. In light of this development we studied the natural course of cases not fitting the definition of classic infantile Pompe's disease. Our review of 109 reports including 225 cases shows a continuous spectrum of phenotypes. The onset of symptoms ranged from 0 to 71 years. Based on the available literature, no criteria to delineate clinical sub-types could be established.A common denominator of these cases is that first symptoms were related to or caused by muscle weakness. In general, patients with a later onset of symptoms seemed to have a better prognosis. Respiratory failure was the most frequent cause of death. CK, LDH, ASAT, ALAT and muscle glycogen levels were frequently but not always elevated. In most cases a muscle biopsy revealed lysosomal pathology, but normal muscle morphology does not exclude Pompe's disease. In 10% of the cases in which the enzyme assay on leukocytes was used, a normal alpha-glucosidase activity was reported. Data on skeletal muscle strength and function, pulmonary function, disability, handicap and quality of life were insufficiently reported in the literature. Studies of non-classic Pompe's disease should focus on these aspects, before enzyme replacement therapy becomes generally available.
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PMID:The natural course of non-classic Pompe's disease; a review of 225 published cases. 2161 30

The rigid spine syndrome is a disorder characterized by proximal muscle weakness and limitation in flexion of the cervical and dorsolumbar spine. Such phenotype may be caused by a variety of hereditary myopathies. We present the case of a 15-years-old boy with rigid spine syndrome and severe restrictive respiratory changes. Muscle biopsy revealed vacuolar myopathy with excessive deposition of PAS-positive material. Lysosomal acid maltase activity in cultured skin fibroblasts was reduced to 6% of control values. DNA analysis demonstrated novel mutation E888X of acid alpha-glucosidase gene with compound heterozygosity IVS1/E888X, confirming diagnosis of Pompe disease. We conclude that acid maltase deficiency should be considered in the diagnosis of rigid spine syndrome.
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PMID:Juvenile onset acid maltase deficiency presenting as a rigid spine syndrome. 1653 Oct 44

Hereditary autophagic vacuolar myopathy (AVM) may occur in several diseases including the rimmed vacuolar myopathies, acid maltase deficiency, Danon disease, infantile autophagic vacuolar myopathy and X-linked myopathy with excessive autophagy (XMEA). In the latter three conditions the vacuoles are lined by membranes with sarcolemmal features. We present two unusual cases of autophagic vacuolar myopathy in twin girls born at term with no family history of neurological disease. After initial normal developmental milestones they developed progressive leg weakness and wasting with contractures from the age of 12 years. Investigations showed raised CK, normal female karyotype, normal acid maltase activity, normal nerve conduction and myopathic EMG features. Frozen sections of skeletal muscle were stained using routine tinctorial and histochemical methods. Immunohistochemical staining for spectrin, merosin, dystrophin, complement membrane attack complex and sarcoglycans was performed and ultrastructural examination undertaken. Direct sequence analysis of the lamp-2 gene using genomic DNA extracted from lymphocytes was performed. Histological analysis of the muscle biopsies demonstrated myofibres with vacuoles lacking glycogen and lipid many of which were delineated using immunohistochemistry for merosin, dystrophin and sarcoglycans. Ultrastructural examination showed duplication of the myofibre basal lamina with associated autophagic material. Vacuoles within myofibres were either membrane bound containing autophagic material or lined by plasma membrane and basal lamina. Intermyofibrillar glycogen was increased. Sequence analysis of the coding region and intron/exon boundaries of the lamp-2 gene was normal. This is the first report of female cases of AVM with sarcolemmal features. We suggest that these patients may represent manifesting carriers of XMEA, or alternatively, a new form of disease with a similar phenotype having autosomal recessive inheritance.
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PMID:Autophagic vacuolar myopathy in twin girls. 1664 Jun 43

Pompe disease (Glycogen storage disease type II, GSDII, or acid maltase deficiency) is an autosomal recessive disorder characterized by deficiency of acid alpha-glucosidase resulting in intra-lysosomal accumulation of glycogen and leading to progressive muscle dysfunction. The natural history of infantile-onset Pompe disease is characterized by hypertrophic cardiomyopathy and profound generalized weakness presenting in the first few months of life, with rapid progression and death usually occurring by one year of age. Late-onset Pompe disease is characterized by onset of symptoms after one year of age, less severe or absence of cardiac involvement and slower progression, with symptoms primarily related to progressive dysfunction of skeletal muscles and respiratory muscle involvement. Recent clinical trials of enzyme replacement therapy have begun to allow greater opportunity for potential improvement in motor status, function, and survival than ever before, with hopes of moving toward maximizing physical function for individuals with Pompe disease. Children are living longer with some achieving independent sitting, creeping, and walking-milestones typically never achieved in the untreated natural history of the disorder. With increased survival, clinical management based on an understanding of the pathology and pathokinesiology of motor function gains importance. This article reviews current knowledge regarding the motor system in Pompe disease and provides an overview of physical therapy management of Pompe disease, including management strategies for individuals on enzyme replacement therapy.
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PMID:Physical therapy management of Pompe disease. 1670 83

Eight patients with adult-onset type II glycogenosis (GSD II), all carrying the IVS1-13T<G mutation, were treated with high-protein isocaloric diet for 3 years. We evaluated the usefulness of this approach through the assessment of the skeletal muscles (by manual muscle testing, quantitative isokinetic exercise, and muscle MRI) and the respiratory function (by spirometry). Three patients with mild or moderate disease severity refused the diet and were still monitored for comparison: they showed clinical (2 patients) or clinicoradiological (1 patient) progression of muscle weakness, while respiratory function remained unchanged. Among the patients accepting the dietary treatment, muscle strength remained unchanged, as did the degree of fatty infiltration and atrophy as assessed by muscle MRI; respiratory function worsened in 2/5 patients with severe baseline respiratory dysfunction. High-protein diet may stabilize disease progression at the skeletal muscles, but does not produce significant clinical improvements; moreover, the usefulness of this approach in patients with severe respiratory disease seems questionable.
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PMID:Dietary treatment in adult-onset type II glycogenosis. 1678 56

We present seven cases of Pompe disease (McKusick 232300; glycogen storage disease type II; acid maltase deficiency) from Greece. The onset of symptoms varied from early childhood to late adulthood, and the patients had quite variable duration of disease. All but one of them had muscle weakness and all had mildly to highly elevated serum creatine kinase. The diagnosis in all cases was confirmed by the finding of acid alpha-glucosidase (EC 3.2.1.3/20) deficiency in cultured skin fibroblasts. Thirteen mutant alleles were identified and nine different pathogenic mutations were encountered. Four were new: c.2071_2072insAGCCG leads to frameshift and total loss of function; c.1856G > A (p.Ser619Asn) leads to 90-95% loss of function; and the splice-site mutations c.1552-3C > G and c.2331+4A > G reduce the number of correct splicing events by more than 90%. The splice-site mutation c.-32-13T > G (IVS1-13T > G) was encountered four times and seems equally common among Greek and other caucasians. The other mutations: c.925G > A (p.Gly309Arg), c.[307T > G; 271G > A] (p.Cys103Gly; Asp91Asn), c.271del and c.1655T > C (p.Leu552Pro) have been reported earlier. Our study highlights the heterogeneity of Pompe disease in Greece and provides tools for diagnosis and carrier detection.
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PMID:Seven cases of Pompe disease from Greece. 1683 77

In Pompe disease, a genetic deficiency of lysosomal acid alpha-glucosidase, glycogen accumulates abnormally in the lysosomes of skeletal, cardiac and smooth muscle, and contributes to clinically progressive and debilitating muscle weakness. The present study involved 8 infantile-onset Pompe patients, treated weekly with 10 mg/kg of recombinant human acid alpha-glucosidase (rhGAA). Muscle biopsies were obtained at baseline, 12 and 52 weeks post-treatment to establish an indicator of efficacy. Several histologic strategies were employed to characterize changes in pre- and post-treatment samples, including high-resolution light microscopy and digital histomorphometry, electron microscopy, capillary density and fiber type analysis, and confocal microscopy for satellite cell activation analysis. Histomorphometric analysis was performed on muscle samples to assess glycogen depletion in response to enzyme replacement therapy (ERT). The extent of glycogen clearance varied widely among these patient samples, and correlated well with clinical outcome. Low glycogen levels, mild ultrastructural damage, a high proportion of type I fibers, and young age at baseline were all features associated with good histologic response. There was no correlation between capillary density and glycogen clearance, and activated satellite cell levels were shown to be higher in post-treatment biopsies with poor histologic responses. This histopathologic study of infantile Pompe disease provides detailed insight into the cellular progression of the disease and its response to therapy while highlighting a number of methodologies which may be employed to assess regression or progression of the associated pathology. As enzyme replacement therapy becomes more prevalent for the treatment of lysosomal storage diseases, such evaluation of post-treatment pathology will likely become a more common occurrence in the daily practice of pathologists.
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PMID:Characterization of pre- and post-treatment pathology after enzyme replacement therapy for Pompe disease. 1707 80

Glycogen storage disease type II (GSDII; Pompe disease or acid maltase deficiency) is an autosomal recessive disorder caused by lysosomal acid alpha-glucosidase (AalphaGlu) deficiency and manifests predominantly as skeletal muscle weakness. Defects in post-translational modification and transport of mutant AalphaGlu species are frequently encountered and may potentially be corrected with chaperone-mediated therapy. In the present study, we have tested this hypothesis by using deoxynojirimycin and derivatives as chemical chaperones to correct the AalphaGlu deficiency in cultured fibroblasts from patients with GSDII. Four mutant phenotypes were chosen: Y455F/Y455F, P545L/P545L, 525del/R600C and D645E/R854X. In case of Y455F/Y455F and P545L/P545L, N-(n-butyl)deoxynojirimycin (NB-DNJ) restored the transport, maturation and activity of AalphaGlu in a dose dependent manner, while it had no effect on the reference enzyme beta-hexosaminidase. NB-DNJ promoted export from the endoplasmic reticulum (ER) to the lysosomes and stabilized the activity of mutant AalphaGlu species, Y455F and P545L, inside the lysosomes. In long-term culture, the AalphaGlu activity in the fibroblasts from the patients with mutant phenotypes, Y455F/Y455F and P545L/P545L, increased up to 14.0- and 7.9-fold, respectively, in the presence of 10mumol/L NB-DNJ. However, the effect of NB-DNJ on Y455F/Y455F subsided quickly after removal of the compound. We conclude that NB-DNJ acts in low concentration as chemical chaperone for certain mutant forms of AalphaGlu that are trapped in the ER, poorly transported or labile in the lysosomal environment. Chemical chaperone therapy could create new perspectives for therapeutic intervention in GSDII.
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PMID:Chemical chaperones improve transport and enhance stability of mutant alpha-glucosidases in glycogen storage disease type II. 1709 74

Pompe disease is a rare autosomal recessive disease caused by the deficiency of acid alpha-glucosidase (GAA), which is required for the degradation of lysosomal glycogen. Glycogen accumulation in heart, muscle and liver eventually leads to muscle weakness, hepatomegaly and cardiomegaly. Although an approved therapy does not exist, the efficacy of enzyme replacement therapy (ERT) has recently been reported in multinational trials in Europe and the US. Here, we present data on the efficacy of recombinant human acid alpha-glucosidase (rhGAA) (provided by Genzyme Corporation) in a patient with Pompe disease. At 5 months of age, motor delay (could not raise his head) and cardiomegaly were observed. A definite diagnosis of Pompe disease was made at 8 months of age after the accumulation of glycogen in a muscle biopsy specimen was observed. This was confirmed by low GAA activity. Since then, motor delay predominated and he was unable to sit independently by age 2.5 years. Every 2 weeks, 20 mg/kg of rhGAA was infused intravenously. To assess the effectiveness, chest X-ray, echocardiography and auditory brain response were recorded. The patient was administered rhGAA for 26 months from 2 years and 8 months of age. Following the initiation of ERT, hepatomegaly and cardiac function (ejection fraction) were rapidly improved and motor function was gradually improved. At 4 years and 10 months, the patient could walk with support. No adverse event has been observed. It can be concluded that ERT with rhGAA is an effective and safe regimen for this case.
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PMID:[Enzyme replacement therapy in a patient with Pompe disease]. 1787 14

Metabolic myopathies are inborn errors of intermediate muscle metabolism, presenting either by exercise intolerance, or by progressive muscle weakness. Growing knowledge concerning the pathophysiology of these rare disorders, and the development of new technologies, opens new avenues for the treatment of this group of myopathies. Recent studies showed improvement in exercise capacity after regular aerobic exercise training in patients with McArdle's disease and mitochondrial myopathies. In late-onset Pompe disease enzyme replacement therapy trials with recombinant acid alpha-glucosidase (Myozyme) are currently in progress, the first trials conducted in childhood onset Pompe disease having previously shown a clear improvement in life expectancy and cardiac function. The demonstration that fibrates can induce correction of carnitine palmitoyl-transferase II deficiency in patients cells, lead to the development of an open-labelled therapeutic trial with bezafibrate in patients with CPTII deficiency, which is actually ongoing.
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PMID:[New approaches for the treatment of metabolic myopathies]. 1803 29


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