Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cases of two Japanese siblings with adult-onset sialidosis type I are reported. A 38-year-old man had gradually developed involuntary movement of the extremities from the age of 31. On admission, he had no skeletal abnormalities and hepatosplenomegaly, but showed myoclonus of the extremities and dyskinesia in the perioral region. We found cherry-red spots and a giant potential in a somatosensory evoked potential (SEP) study. Then, the diagnosis of sialidosis type I was confirmed by low activity of white blood cell sialidase. MRI (SE, TR 2,000/TE 100, 40) of the brain revealed a small high intensity are in the cerebral white matter adjacent to the posterior horn of the right cerebral ventricle. To our knowledge, no report on MRI findings of the brain in sialidosis type I has been reported. So far, it is uncertain whether or not such a lesion is caused by sialidosis. He was treated with clonazepam, sodium valproate, diphenylhydantoin, or haloperidol. The former two improved the symptoms, but SEP findings did not change. The subject's 43-year-old brother had also myoclonus and epilepsy since the age of 31, and low activity of sialidase. Their mother had no symptoms, but her sialidase activity level was as low as that of a carrier. These two are the eighth and ninth cases of sialidosis type I in Japan to be confirmed by enzyme activity.
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PMID:[Two siblings with adult-onset sialidosis type I (cherry-red spot-myoclonus syndrome)]. 877 7

Two brothers, aged 34 and 30 showed signs of gargoylism, macular cherry-red spots, angiokeratoma, vertebral deformities, epilepsy, action myoclonus and ataxia. In 1985, they were diagnosed as juvenile galactosialidosis due to the decrease in activity of beta-galactosidase and neuraminidase when they had slight valvular involvement with mild heart murmur. On admission in 1994, their echocardiograms revealed marked progression of the cardiac involvement, i.e. thickening of the valvular and left ventricular wall with valvular regurgitation. These findings suggested that accumulation of abnormal materials was increased during the past 10 years. The change in the echocardiographic findings was more severe in the younger brother who had milder physical and neurological manifestations, although severity of neurological symptoms correlated with those of other symptoms in some reports. This study indicates that an evaluation in cardiac involvement may be very important in patients with galactosialidosis, even those with very mild neurological manifestations. Thus echocardiogram is very useful for this purpose.
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PMID:[Two siblings of galactosialidosis with marked progression of cardiac involvement during 10 years]. 881 Aug 50

Sialidase (neuraminidase, EC 3.2.1.18) catalyses the hydrolysis of terminal sialic acid residues of glyconjugates. Sialidase has been well studied in viruses and bacteria where it destroys the sialic acid-containing receptors at the surface of host cells, and mobilizes bacterial nutrients. In mammals, three types of sialidases, lysosomal, plasma membrane and cytosolic, have been described. For lysosomal sialidase in humans, the primary genetic deficiency results in an autosomal recessive disease, sialidosis, associated with tissue accumulation and urinary excretion of sialylated oligosaccharides and glycolipids. Sialidosis includes two main clinical variants: late-onset, sialidosis type I, characterized by bilateral macular cherry-red spots and myoclonus, and infantile-onset, sialidosis type II, characterized by skeletal dysplasia, mental retardation and hepatosplenomegaly. We report the identification of human lysosomal sialidase cDNA, its cloning, sequencing and expression. Examination of six sialidosis patients revealed three mutations, one frameshift insertion and two missense. We mapped the lysosomal sialidase gene to human chromosome 6 (6p21.3), which is consistent with the previous chromosomal assignment of this gene in proximity to the HLA locus.
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PMID:Cloning, expression and chromosomal mapping of human lysosomal sialidase and characterization of mutations in sialidosis. 905 50

Two cases of non-immunological hydrops fetalis (NIHF) presenting with massive ascites are reported; in both patients an oligosaccharid-pattern in the urine typical for sialidosis resp. galactosialidosis was found. The cerebral sonography of both patients showed streaky echo enhancement in the region of the thalamostriatal vessels, which was interpreted as calcification of the vessels. The courses of the patients were characterised by recurrent infections, hepatosplenomegaly and myoclonus. Relevant literature reports on a large variability in the clinical appearance of oligosaccharidoses. The diagnosis of sialidosis is confirmed in cultured fibroblasts by the deficiency of alpha-N-acetylneuraminidase and, in case of galactosialidosis by the additional lack of beta-galactosidase. The precise diagnosis in NIHF is of increasing interest for prenatal diagnostic as well as for neonatological management.
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PMID:[Sialidosis and galactosialidosis as the cause of non-immunologic hydrops fetalis]. 944 Sep 57

We examined a patient with adult onset sialidosis using N-isopropyl-p-123I-iodoamphetamine single photon emission computed tomography (SPECT) and 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography (PET). A 41-year-old [correction of 47] man was admitted to our hospital because of the involuntary movement of his extremities and gait disturbance. On admission, he exhibited action myoclonus in his face and extremities with cerebellar ataxia. Ophthalmoscopy revealed cherry-red spots on his retina. Enzymological analysis of his leucocytes and skin fibroblasts revealed primary sialidase deficit. Brain MRI showed no abnormal findings. Brain SPECT showed decreased cerebral blood flow in the cortex of bilateral occipital lobes, and PET study revealed decreased glucose metabolism in the cortex of bilateral occipital lobes. This case is the thirteenth patient of adult onset sialidosis in Japan. As far as we know, there are no previous reports of SPECT or PET on sialidosis patients. Why the cerebral blood flow and glucose metabolism was decreased in the occipital lobe region remains obscure. From the literatures, we suppose that the onset time of neuronal tissue degeneration or the sensitivity to cumulative metabolites in the occipital region may be different from those in other regions. Further studies are required to confirm abnormalities of cerebral blood flow and metabolism in sialidosis.
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PMID:[Neuroradiological findings on cerebral blood flow and metabolism of a case of adult onset sialidosis]. 950 67

Among the epilepsies, the progressive myoclonus epilepsies (PMEs) form a heterogeneous group of rare diseases characterized by myoclonus, epilepsy, and progressive neurologic deterioration, particularly dementia and ataxia. The success of the Human Genome Project and the fact that most PMEs are inherited through a mendelian or mitochondrial mode have resulted in important advances in the definition of the molecular basis of PME. The gene defects for the most common forms of PME (Unverricht-Lundborg disease, the neuronal ceroid lipofuscinoses, Lafora disease, type I sialidosis, and myoclonus epilepsy with ragged-red fibers) have been either identified or mapped to specific chromosome sites. Unverricht-Lundborg disease has been shown to be caused by mutations in the gene that codes for cystatin B, an inhibitor of cysteine protease. The most common mutation in Unverricht-Lundborg disease is an expansion of a dodecamer repeat located in a noncoding region upstream of the transcription start site of the cystatin B gene, making it the first human disease associated with instability of a dodecamer repeat. Juvenile neuronal ceroid lipofuscinosis is caused by mutations in the CLN3 gene, a gene of unknown function that encodes a 438-amino-acid protein of possible mitochondrial location. Other forms of neuronal ceroid lipofuscinosis that occur as PME and Lafora disease have been mapped by means of linkage analysis, but the corresponding gene defects remain unknown. Sialidosis has been shown to be caused by mutations in the sialidase gene, and myoclonus epilepsy with ragged-red fibers is well known to be caused by mutations in the mitochondrial gene that codes for tRNA(Lys). How the different PME gene defects described produce the various PME phenotypes, including epileptic seizures, remains unknown. The development of animal models that bear these mutations is needed to increase our knowledge of the basic mechanisms involved in the PMEs. This knowledge should lead to the development of new and effective forms of therapy, which are especially lacking for the PMEs.
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PMID:The molecular genetic bases of the progressive myoclonus epilepsies. 1051 28

We describe 3-year clinical course of a 54-year-old Japanese man who presented with action myoclonus, parkinsonism and epilepsy. There was no family history or consanguinity. The patient was well until the age of 51 years (in 1986), when he noted slow movements, memory disturbance and left hand tremor. He was treated with anti-Parkinson drugs without any improvements. Soon thereafter, he developed a gait disturbance and generalized tonic clonic seizures. He was admitted to our service at the age of 53 years. General physical examination revealed no hepatosplenomegaly. Neurological examination showed mild dementia. Neither retinal pigmentation nor cherry red spot was noted. He was unable to walk due to marked frozen gait. His upward gaze was limited and saccadic eye movement was slow. He had action myoclonus in both upper extremities and resting tremor on the left side. He showed mild left hemiparesis. Deep tendon reflex was hyperactive in both side with extensor plantar responses. MRI demonstrated cortical atrophy, especially marked at the bilateral temporal lobes with a right side predominance. Leukocyte lysosomal enzyme activities of beta-hexosaminidase, beta-galactosidase and sialidase were within normal limits. The patient died of pneumonia on April 25, 1989. At the time of a neurological CPC, neurologists reached the clinical diagnosis of adult-type neuronal ceroid-lipofuscinosis. Postmortem examination revealed bilateral bronchopneumonia. The brain weighed 1,219 g and showed atrophy of the temporal lobes. Histological examination showed neuronal cells with swollen cytoplasm and lipofuscin-like granules throughout the CNS, including the cerebral cortex, thalamus, substantia nigra, motor nuclei of the brain stem, dentate nuclei, inferior olivary nuclei. Clarke's nuclei and anterior horn cells. Marked neuronal loss was noted in the right temporal lobe and substantia nigra. Electron micrographs of the frontal cortex revealed "fingerprint profiles" in the cytoplasm of neuronal and glial cells. Pathological findings were consistent with the diagnosis of adult-type neuronal ceroid-lipofuscinosis (Kufs' disease).
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PMID:[A 54-year-old man with action myoclonus, parkinsonism and epilepsy]. 1058 20

Sialidosis is an autosomal recessive disease caused by the genetic deficiency of lysosomal sialidase, which catalyzes the hydrolysis of sialoglycoconjugates. The disease is associated with progressive impaired vision, macular cherry-red spots and myoclonus (sialidosis type I) or with skeletal dysplasia, Hurler-like phenotype, dysostosis multiplex, mental retardation and hepatosplenomegaly (sialidosis type II). We have analyzed the genomic DNA from nine sialidosis patients of multiple ethnic origin in order to find mutations responsible for the enzyme deficiency. The activity of the identified variants was studied by transgenic expression. One patient had a frameshift mutation (G623delG deletion), which introduced a stop codon, truncating 113 amino acids. All others had missense mutations: G679G-->A (Gly227Arg), C893C-->T (Ala298Val), G203G-->T (Gly68Val), A544A-->G (Ser182Gly) C808C-->T (Leu270Phe) and G982G-->A (Gly328Ser). We have modeled the three-dimensional structure of sialidase based on the atomic coordinates of the homologous bacterial sialidases, located the positions of mutations and estimated their potential effect. This analysis showed that five mutations are clustered in one region on the surface of the sialidase molecule. These mutations dramatically reduce the enzyme activity and cause a rapid intralysosomal degradation of the expressed protein. We hypothesize that this region may be involved in the interface of sialidase binding with lysosomal cathepsin A and/or beta-galactosidase in their high-molecular-weight complex required for the expression of sialidase activity in the lysosome.
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PMID:Characterization of the sialidase molecular defects in sialidosis patients suggests the structural organization of the lysosomal multienzyme complex. 1076 32

Sialidosis is an autosomal recessive disease caused by the genetic deficiency of lysosomal sialidase, which catalyzes the catabolism of sialoglycoconjugates. The disease is associated with progressive impaired vision, macular cherry-red spots, and myoclonus (sialidosis type I) or with skeletal dysplasia, Hurler-like phenotype, dysostosis multiplex, mental retardation, and hepatosplenomegaly (sialidosis type II). We analyzed the effect of the missense mutations G68V, S182G, G227R, F260Y, L270F, A298V, G328S, and L363P, which are identified in the sialidosis type I and sialidosis type II patients, on the activity, stability, and intracellular distribution of sialidase. We found that three mutations, F260Y, L270F, and A298V, which are clustered in the same region on the surface of the sialidase molecule, dramatically reduced the enzyme activity and caused a rapid intralysosomal degradation of the expressed protein. We suggested that this region might be involved in sialidase binding with lysosomal cathepsin A and/or beta-galactosidase in the multienzyme lysosomal complex required for the expression of sialidase activity. Transgenic expression of mutants followed by density gradient centrifugation of cellular extracts confirmed this hypothesis and showed that sialidase deficiency in some sialidosis patients results from disruption of the lysosomal multienzyme complex.
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PMID:Mutations in sialidosis impair sialidase binding to the lysosomal multienzyme complex. 1127 74

Galactosialidosis is a lysosomal storage disease associated with a combined deficiency of beta-galactosidase and neuraminidase, caused by a defect of another lysosomal protein, the protective protein. Three subtypes are recognized: the early infantile form, the late infantile form and the juvenile/adult form. We saw a patient with galactosialidosis of the juvenile/adult form, a 51-year-old Japanese man with angiokeratomas on both elbows and knees, myoclonus, ataxia, mental retardation and macular cherry-red spots. An electron-microscopic study of a skin biopsy showed membrane-limited vacuoles in the cytoplasm of the endothelial cells, pericytes and fibroblasts. Assays of enzymatic activity in cultured fibroblasts showed a marked decrease in both beta-galactosidase and neuraminidase (sialidase). The substance contained in the cytoplasmic vacuoles appears to be glycoproteins with sialic acid, which is a terminal glycosyl residue, because the cytoplasm of the endothelial cells of the vessels and pericytes are stained by the Limax flavus agglutinin, a lectin that binds specifically with sialic acid. This technology may be useful for easy investigation of the distribution of the accumulation of such substances in the central nervous system.
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PMID:A case of galactosialidosis. 1293 52


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