title: Should genetic testing for SCAs be included in the diagnostic workup for MSA?
abstract: OBJECTIVE
  To examine the prevalence of mutations in spinocerebellar ataxia (SCA) genes in patients who were clinically diagnosed with multiple system atrophy (MSA).
  
  
  METHODS
  Genetic tests for SCA were performed in 302 of 528 patients who met the diagnostic criteria for MSA based on clinical features. Generally, when a patient had cerebellar symptoms or cerebellar atrophy on neuroimaging, genetic tests for SCA types 1, 2, 3, 6, 7, and 17, and dentatorubropallidoluysian atrophy were done, and when a patient had parkinsonism without cerebellar symptoms, genetic tests for SCA types 2, 3, and 17 were done.
  
  
  RESULTS
  Mutations in SCA genes were found in 22 of the 302 patients (7.3%) with SCA17 comprising more than half of the mutation-positive cases. The age at disease onset in these 22 patients was not different compared with the 280 patients without mutations (55.9 ± 9.3 vs 59.2 ± 8.9, p = 0.102). All patients had urinary symptoms, and 10 patients also had orthostatic dizziness or orthostatic hypotension. A family history was reported in only 3 patients. Of note, dream enactment behavior suggesting REM sleep behavior disorder was reported in 9 of the 11 patients (81.8%) asked.
  
  
  CONCLUSIONS
  The high proportion of patients with SCA mutations in this study indicates that genetic testing for SCA should be included for patients with MSA, especially for patients with cerebellar dysfunctions.
authors.affiliation: From the Department of Neurology and Movement Disorder Center (H.-J.K., B.S.J., J.S., W.-W.L., H.P.), Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University; Department of Neurology (Y.J.J.), Kyung Hee University Hospital at Gangdong, Seoul; and Department of Neurology (G.E.), Myongji Hospital, Goyang-si, Kyongki-do, Korea.
authors.forename: Han-Joon
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: From the Department of Neurology and Movement Disorder Center (H.-J.K., B.S.J., J.S., W.-W.L., H.P.), Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University; Department of Neurology (Y.J.J.), Kyung Hee University Hospital at Gangdong, Seoul; and Department of Neurology (G.E.), Myongji Hospital, Goyang-si, Kyongki-do, Korea. brain@snu.ac.kr.
authors.forename: Beom S
authors.initials: BS
authors.lastname: Jeon
authors.affiliation: From the Department of Neurology and Movement Disorder Center (H.-J.K., B.S.J., J.S., W.-W.L., H.P.), Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University; Department of Neurology (Y.J.J.), Kyung Hee University Hospital at Gangdong, Seoul; and Department of Neurology (G.E.), Myongji Hospital, Goyang-si, Kyongki-do, Korea.
authors.forename: Junghwan
authors.initials: J
authors.lastname: Shin
authors.affiliation: From the Department of Neurology and Movement Disorder Center (H.-J.K., B.S.J., J.S., W.-W.L., H.P.), Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University; Department of Neurology (Y.J.J.), Kyung Hee University Hospital at Gangdong, Seoul; and Department of Neurology (G.E.), Myongji Hospital, Goyang-si, Kyongki-do, Korea.
authors.forename: Woong-Woo
authors.initials: WW
authors.lastname: Lee
authors.affiliation: From the Department of Neurology and Movement Disorder Center (H.-J.K., B.S.J., J.S., W.-W.L., H.P.), Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University; Department of Neurology (Y.J.J.), Kyung Hee University Hospital at Gangdong, Seoul; and Department of Neurology (G.E.), Myongji Hospital, Goyang-si, Kyongki-do, Korea.
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Park
authors.affiliation: From the Department of Neurology and Movement Disorder Center (H.-J.K., B.S.J., J.S., W.-W.L., H.P.), Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University; Department of Neurology (Y.J.J.), Kyung Hee University Hospital at Gangdong, Seoul; and Department of Neurology (G.E.), Myongji Hospital, Goyang-si, Kyongki-do, Korea.
authors.forename: Yu Jin
authors.initials: YJ
authors.lastname: Jung
authors.affiliation: From the Department of Neurology and Movement Disorder Center (H.-J.K., B.S.J., J.S., W.-W.L., H.P.), Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University; Department of Neurology (Y.J.J.), Kyung Hee University Hospital at Gangdong, Seoul; and Department of Neurology (G.E.), Myongji Hospital, Goyang-si, Kyongki-do, Korea.
authors.forename: Gwanhee
authors.initials: G
authors.lastname: Ehm
mesh_terms: D017668:Age of Onset; D000368:Aged; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000150:complications / Q000175:diagnosis / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D012189:Retrospective Studies; D020754:Spinocerebellar Ataxias / Q000150:complications / Q000175:diagnosis / Q000235:genetics