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)

Thirteen patients with galactosialidosis (beta-galactosidase-neuraminidase deficiency) from 9 families including two autopsy cases were studied from clinical, genetic, cytological and biochemical standpoints. Coarse facies, myoclonus, cerebellar ataxia, angiokeratoma, loss of vision, corneal opacity and cherry-red spots were the main signs and symptoms although these clinical manifestations were widely variable in individual cases. It is not yet known whether these clinical variations represent genetic heterogeneity or not. Deficiency of beta-galactosidase and neuraminidase was the most prominent biochemical abnormality in this disease. Beta-Galactosidase activity was restored in fibroblasts when serine-thiol protease inhibitors were added to the culture medium. Cathepsin B activity was significantly high in fibroblasts, liver and brain from the patients. It was demonstrated that neuraminidase was susceptible to the procedures for disrupting cells and tissues, such as sonication and freezing. The stability of this enzyme may be dependent on the molecular state in relation to cell membranes.
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PMID:Galatosialidosis (beta-galactosidase-neuraminidase deficiency): clinical and biochemical studies on 13 patients. 681 2

The progressive myoclonus epilepsies, featuring the triad of myoclonus, seizures, and ataxia, comprise a large group of inherited neurodegenerative diseases that remain poorly understood and refractory to treatment. The Cystatin B gene is mutated in one of the most common forms of progressive myoclonus epilepsy, Unverricht-Lundborg disease (EPM1). Cystatin B knockout in a mouse model of EPM1 triggers progressive degeneration of cerebellar granule neurons. Here, we report impaired redox homeostasis as a key mechanism by which Cystatin B deficiency triggers neurodegeneration. Oxidative stress induces the expression of Cystatin B in cerebellar granule neurons, and EPM1 patient-linked mutation of the Cystatin B gene promoter impairs oxidative stress induction of Cystatin B transcription. Importantly, Cystatin B knockout or knockdown sensitizes cerebellar granule neurons to oxidative stress-induced cell death. The Cystatin B deficiency-induced predisposition to oxidative stress in neurons is mediated by the lysosomal protease Cathepsin B. We uncover evidence of oxidative damage, reflected by depletion of antioxidants and increased lipid peroxidation, in the cerebellum of Cystatin B knock-out mice in vivo. Collectively, our findings define a pathophysiological mechanism in EPM1, whereby Cystatin B deficiency couples oxidative stress to neuronal death and degeneration, and may thus provide the basis for novel treatment approaches for the progressive myoclonus epilepsies.
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PMID:Cystatin B deficiency sensitizes neurons to oxidative stress in progressive myoclonus epilepsy, EPM1. 1942 Feb 57