title: Bicuspid aortic valve morphology and associated cardiovascular abnormalities in fetal Turner syndrome: a pathomorphological study.
abstract: BACKGROUND
  Bicuspid aortic valve (BAV) is common in Turner syndrome (TS). In adult TS, 82-95% of BAVs have fusion of the right and left coronary leaflets. Data in fetal stages are scarce. The purpose of this study was to gain insight into aortic valve morphology and associated cardiovascular abnormalities in a fetal TS cohort with adverse outcome early in development.
  
  
  METHODS
  We studied post-mortem heart specimens of 36 TS fetuses and 1 TS newborn.
  
  
  RESULTS
  BAV was present in 28 (76%) hearts. BAVs showed fusion of the right and left coronary leaflet (type 1 BAV) in 61%, and fusion of the right coronary and non-coronary leaflet (type 2 BAV) in 39%. There were no significant differences in occurrence of additional cardiovascular abnormalities between type 1 and type 2 BAV. However, all type 2 BAV hearts showed ascending aorta hypoplasia and tubular hypoplasia of the B segment, as opposed to only 55 and 64% of type 1 BAV hearts, respectively.
  
  
  CONCLUSIONS
  The proportion of type 2 BAV seems higher in TS fetuses than in adults. Fetal type 2 BAV hearts all had severe aortic pathology, possibly contributing to a worse prognosis of type 2 than type 1 BAV in TS.
authors.affiliation: Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Klaartje
authors.initials: K
authors.lastname: van Engelen
authors.forename: Margot M
authors.initials: MM
authors.lastname: Bartelings
authors.forename: Adriana C
authors.initials: AC
authors.lastname: Gittenberger-de Groot
authors.forename: Marieke J H
authors.initials: MJ
authors.lastname: Baars
authors.forename: Alex V
authors.initials: AV
authors.lastname: Postma
authors.forename: Emilia K
authors.initials: EK
authors.lastname: Bijlsma
authors.forename: Barbara J M
authors.initials: BJ
authors.lastname: Mulder
authors.forename: Monique R M
authors.initials: MR
authors.lastname: Jongbloed
mesh_terms: D001021:Aortic Valve / Q000002:abnormalities* / Q000196:embryology / Q000473:pathology; D000082882:Bicuspid Aortic Valve Disease; D018376:Cardiovascular Abnormalities / Q000196:embryology / Q000473:pathology; D005260:Female; D005318:Fetal Heart / Q000002:abnormalities* / Q000196:embryology / Q000473:pathology*; D006321:Heart / Q000196:embryology; D006349:Heart Valve Diseases / Q000196:embryology / Q000473:pathology*; D006801:Humans; D007231:Infant, Newborn; D014424:Turner Syndrome / Q000196:embryology / Q000473:pathology*