title: Atypical hemolytic uremic syndrome: Korean pediatric series.
abstract: BACKGROUND
  Atypical hemolytic uremic syndrome (aHUS) is a rare disease with a genetic predisposition. Few studies have evaluated the disease in the Asian population. We studied a Korean pediatric cohort to delineate the clinical characteristics and genotypes.
  
  
  METHODS
  A multicenter cohort of 51 Korean children with aHUS was screened for mutations using targeted exome sequencing covering 46 complement related genes. Anti-complement-factor-H autoantibody (anti-CFH) titers were measured. Multiplex ligation-dependent probe amplification assay was performed to detect deletions in the complement factor-H related protein genes (CFHR) in the patients as well as in 100 healthy Korean controls. We grouped the patients according to etiology and compared the clinical features using Mann-Whitney U-test and chi-squared test.
  
  
  RESULTS
  Fifteen patients (group A, 29.7%) had anti-CFH, and mutations were detected in 11 (group B, 21.6%), including one with combined mutations. The remaining 25 (group C, 49.0%) were negative for both. The prevalence of anti-CFH was higher than the worldwide level. Group A had a higher onset age than group B, although the difference was not significant. Group B had the worst renal outcome. Gene frequencies of homozygous CFHR1 deletion were 73.3%, 2.7% and 1% in group A, group B + C and the control, respectively.
  
  
  CONCLUSIONS
  The incidence of anti-CFH in the present Korean aHUS cohort was high. Clinical outcomes largely conformed to the previous reports. Although the sample size was limited, this cohort provides a reassessment of clinicogenetic features of aHUS in Korean children.
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Jiwon M
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Young Seo
authors.initials: YS
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Joo Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Se Jin
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Severance Children's Hospital, Yonsei University, Seoul, Korea.
authors.forename: Jae Il
authors.initials: JI
authors.lastname: Shin
authors.affiliation: Department of Pediatrics, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: Yong-Hoon
authors.initials: YH
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Kee Hwan
authors.initials: KH
authors.lastname: Yoo
authors.affiliation: Department of Pediatrics, Kyungpook National University Hospital, Daegu, Korea.
authors.forename: Min Hyun
authors.initials: MH
authors.lastname: Cho
authors.affiliation: Department of Pediatrics, Pusan National University Children's Hospital, Yangsan, Korea.
authors.forename: Su-Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Pusan National University Children's Hospital, Yangsan, Korea.
authors.forename: Seong Heon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Wonju College of Medicine, Yonsei University, Wonju, Korea.
authors.forename: Mee Kyung
authors.initials: MK
authors.lastname: Namgoong
authors.affiliation: Department of Pediatrics, Ehwa University Mokdong Hospital, Seoul, Korea.
authors.forename: Seung Joo
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Bundang CHA Hospital, Seongnam, Korea.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Seoul, Korea.
authors.forename: Hee Yeon
authors.initials: HY
authors.lastname: Cho
authors.affiliation: Department of Pediatrics, Jeju University Hospital, Jeju, Korea.
authors.forename: Kyoung Hee
authors.initials: KH
authors.lastname: Han
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.|Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hee Gyung
authors.initials: HG
authors.lastname: Kang
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Il Soo
authors.initials: IS
authors.lastname: Ha
authors.affiliation: Samsung Genome Institute, Samsung Medical Center, Seoul, Korea.|Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea.
authors.forename: Jun-Seok
authors.initials: JS
authors.lastname: Bae
authors.affiliation: Samsung Genome Institute, Samsung Medical Center, Seoul, Korea.
authors.forename: Nayoung K D
authors.initials: NK
authors.lastname: Kim
authors.affiliation: Samsung Genome Institute, Samsung Medical Center, Seoul, Korea.|Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Woong-Yang
authors.initials: WY
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.|Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea.|Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hae Il
authors.initials: HI
authors.lastname: Cheong
mesh_terms: D065766:Atypical Hemolytic Uremic Syndrome / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D017242:Complement Factor H / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D060885:Multiplex Polymerase Chain Reaction; D009154:Mutation; D056910:Republic of Korea / Q000453:epidemiology
chemical_list: D001323:Autoantibodies; D017242:Complement Factor H
keywords: Asian; anti-complement factor H autoantibody; atypical hemolytic uremic syndrome; complement factor H; mutation