title: Expanding sialidosis spectrum by genome-wide screening: NEU1 mutations in adult-onset myoclonus.
abstract: OBJECTIVE
  To identify the genetic cause of a familial form of late-onset action myoclonus in 2 unrelated patients. Both probands had 2 siblings displaying a similar disorder. Extensive laboratory examinations, including biochemical assessment for urine sialic acid in the 2 probands, were negative.
  
  
  METHODS
  Exome sequencing was performed in the probands using an Illumina platform. Segregation analysis of putative mutations was performed in all family members by standard Sanger sequencing protocols.
  
  
  RESULTS
  NEU1 mutations were detected in 3 siblings of each family with prominent cortical myoclonus presenting in the third decade of life and having a mild and slowly progressive course. They did not have macular cherry-red spot and their urinary sialic acid excretion was within normal values. Genetic analysis demonstrated a homozygous mutation in family 1 (c.200G>T, p.S67I) and 2 compound heterozygous mutations in family 2 (c.679G>A, p.G227R; c.913C>T, p.R305C).
  
  
  CONCLUSIONS
  Our observation indicates that sialidosis should be suspected and the NEU1 gene analyzed in patients with isolated action myoclonus presenting in adulthood in the absence of other typical clinical and laboratory findings.
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Canafoglia
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Robbiano
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Pareyson
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Ferruccio
authors.initials: F
authors.lastname: Panzica
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Nanetti
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Giovagnoli
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Venerando
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Gellera
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy. franceschetti@istituto-besta.it.
authors.forename: Silvana
authors.initials: S
authors.lastname: Franceschetti
authors.affiliation: From the Department of Neurophysiopathology and Epilepsy Centre (L.C., F.P., S.F.), Department of Neurology (D.P., L.N.), Laboratory of Cognitive Neurology and Rehabilitation, Neurology and Neuropathology Unit (A.R.G.), and Biochemistry and Genetics Department (A.V., C.G.), IRCCS Foundation C. Besta Neurological Institute, Milan; and Laboratory of Neurogenetics (A.R., F.Z.), Department of Neuroscience, Institute G. Gaslini, Genoa, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Zara
mesh_terms: D000328:Adult; D017668:Age of Onset; D003937:Diagnosis, Differential; D059472:Exome / Q000235:genetics; D005260:Female; D055106:Genome-Wide Association Study / Q000379:methods*; D006801:Humans; D008297:Male; D009081:Mucolipidoses / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D009154:Mutation; D009207:Myoclonus / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D009439:Neuraminidase / Q000235:genetics*; D010375:Pedigree
chemical_list: C486385:NEU1 protein, human; D009439:Neuraminidase