title: Clinical Heterogeneity of Atypical Pantothenate Kinase-Associated Neurodegeneration in Koreans.
abstract: OBJECTIVE
  Neurodegeneration with brain iron accumulation (NBIA) represents a group of inherited movement disorders characterized by iron accumulation in the basal ganglia. Recent advances have included the identification of new causative genes and highlighted the wide phenotypic variation between and within the specific NBIA subtypes. This study aimed to investigate the current status of NBIA in Korea.
  
  
  METHODS
  We collected genetically confirmed NBIA patients from twelve nationwide referral hospitals and from a review of the literature. We conducted a study to describe the phenotypic and genotypic characteristics of Korean adults with atypical pantothenate kinase-associated neurodegeneration (PKAN).
  
  
  RESULTS
  Four subtypes of NBIA including PKAN (n = 30), PLA2G6-related neurodegeneration (n = 2), beta-propeller protein-associated neurodegeneration (n = 1), and aceruloplasminemia (n = 1) have been identified in the Korean population. The clinical features of fifteen adults with atypical PKAN included early focal limb dystonia, parkinsonism-predominant feature, oromandibular dystonia, and isolated freezing of gait (FOG). Patients with a higher age of onset tended to present with parkinsonism and FOG. The p.R440P and p.D378G mutations are two major mutations that represent approximately 50% of the mutated alleles. Although there were no specific genotype-phenotype correlations, most patients carrying the p.D378G mutation had a late-onset, atypical form of PKAN.
  
  
  CONCLUSIONS
  We found considerable phenotypic heterogeneity in Korean adults with atypical PKAN. The age of onset may influence the presentation of extrapyramidal symptoms.
authors.affiliation: Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.
authors.forename: Jae-Hyeok
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea.
authors.forename: Jongkyu
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ho-Sung
authors.initials: HS
authors.lastname: Ryu
authors.affiliation: Department of Neurology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Neurology, Hallym University Sacred Heart Hospital, Anyang, Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Kim
authors.affiliation: Department of Neurology, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Jin Yong
authors.initials: JY
authors.lastname: Hong
authors.affiliation: Department of Pediatrics, Pusan National University Yangsan Hospital, Yangsan, Korea.
authors.forename: Sang Ook
authors.initials: SO
authors.lastname: Nam
authors.affiliation: Department of Neurology, Gachon University Gil Hospital, Incheon, Korea.
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Sung
authors.affiliation: Department of Neurology, Kangwon National University School of Medicine, Chuncheon, Korea.
authors.forename: Seung-Hwan
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.
authors.forename: Jee-Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Neurology, Pusan National University Hospital, Busan, Korea.
authors.forename: Myung Jun
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Department of Neurology, Dong-Eui Hospital, Busan, Korea.
authors.forename: Tae-Hyoung
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Neurology, Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Chul Hyoung
authors.initials: CH
authors.lastname: Lyoo
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sun Ju
authors.initials: SJ
authors.lastname: Chung
authors.affiliation: Department of Neurology, Korea University College of Medicine, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Seong Beom
authors.initials: SB
authors.lastname: Koh
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Phil Hyu
authors.initials: PH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea.
authors.forename: Jin Whan
authors.initials: JW
authors.lastname: Cho
authors.affiliation: Department of Neurology, Yeungnam University Medical Center, Daegu, Korea.
authors.forename: Mee Young
authors.initials: MY
authors.lastname: Park
authors.affiliation: Department of Neurology, Hallym University Sacred Heart Hospital, Anyang, Korea.
authors.forename: Yun Joong
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young H
authors.initials: YH
authors.lastname: Sohn
authors.affiliation: Department of Neurology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Beom Seok
authors.initials: BS
authors.lastname: Jeon
authors.affiliation: Department of Neurology, Korea University College of Medicine, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Myung Sik
authors.initials: MS
authors.lastname: Lee
keywords: Allele frequency; Iron; Neurodegenerative diseases; Pantothenate kinase-associated neurodegeneration; Phenotype
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