Lai S.-C.Chen R.-S.Wu Chou Y.-H.Chang H.-C.Kao L.-Y.Huang Y.-Z.Weng Y.-H.Chen J.-K.WUH-LIANG HWULu C.-S.2020-12-162020-12-1620091351-5101https://www.scopus.com/inward/record.uri?eid=2-s2.0-67651241755&doi=10.1111%2fj.1468-1331.2009.02622.x&partnerID=40&md5=1400998448dff895f90e317d73746c2fhttps://scholars.lib.ntu.edu.tw/handle/123456789/525951Background and purpose: Sialidosis type 1 (ST-1) is a neurodegenerative disorder with limited long-term follow-up report. This study is to document the chronological profile of ST-1. Methods: We perform serial analysis of 17 Taiwanese patients with ST-1 focusing on evolution of clinical features, electrophysiological findings, genetic studies, and neuroimage examinations. Results: All patients had a mutation at 554A→G in exon 3 of the NEU1 gene causing Ser182Gly substitution. Fifteen patients were homozygous. Two patients were heterozygous with novel mutations, 956C→T causing Ala319Val in one and 163C→T causing Gln55stop codon in the other. The neuraminidase activity was markedly decreased in all 11 available patients. Only three patients (17.6%) manifested the macular cherry-red spot. The majority of patients (82.3%) developed full-blown manifestation of myoclonus, ataxia, and seizures within 5 years. Abnormal somatosensory evoked potentials with giant cortical waves were found in all patients. Prolonged P100 peak latency of the visual evoked potentials (VEPs) were found in 16 patients (94.1%) in the early stage even without visual symptoms. Conclusion: ST-1 in Taiwanese population illustrates distinct characteristics of phenotype with infrequent cherry-red spot. We suggest to screen the NEU1 mutations in patients presenting action myoclonus with abnormal VEPs, even without macular cherry-red spots. ? 2009 EFNS.Cherry-red spot myoclonus syndrome; Electrophysiology; Evoked potentials; NEU1 gene; Neuraminidase; Sialidosis type 1[SDGs]SDG3glycine; serine; sialidase; adult; amino acid substitution; article; ataxia; cherry red spot; cherry red spot myoclonus syndrome; clinical article; clinical feature; degenerative disease; early diagnosis; evoked somatosensory response; evoked visual response; exon; female; follow up; gene; gene mutation; heterozygosity; homozygosity; human; longitudinal study; male; myoclonus; NEU1 gene; neuroimaging; priority journal; seizure; sialidosis; sialidosis type 1; stop codon; Taiwan; Adolescent; Adult; Ataxia; Child; Disease Progression; Evoked Potentials, Somatosensory; Evoked Potentials, Visual; Female; Humans; Longitudinal Studies; Male; Mucolipidoses; Mutation, Missense; Myoclonus; Neuraminidase; Neurodegenerative Diseases; Seizures; Taiwan; Young Adultjournal article10.1111/j.1468-1331.2009.02622.x194733592-s2.0-67651241755